The verse was revealed in Makkah (Mawdudi and Anwarul bayan by Shaykh Ashiq Ilahi Madni) 
“Allah presents an example: a slave [who is] owned and unable to do a thing and he to whom We have provided from Us good provision, so he spends from it secretly and publicly. Can they be equal? Praise to Allah ! But most of them do not know.” – Qur’an16:75
All humans in the sight of God are equal. God is not saying, as some have suggested that some are above, except by piety and good action. In fact, this verse is a parable. The verse’s main goal was to show that polytheism is a grave sin, and those who associate partners with God Almighty have committed a major unforgivable sin if they didn’t repent from it.
Furthermore, God here shows them an example, how could an idol that can not benefit them be equal to God? Some of these polytheists used to own slaves in Makkah, and God throws the question at the polytheists if these human
beings who are under them i.e., slaves are not equal to them as they believed, nor would they share their wealth with them, how could they then say that these idols are equal to God? It was a question to make them think and abandon their polytheistic beliefs and accept Monotheism.
Scholar Abdullah Yusuf Ali:
“2107 The first parable is of two men, one of whom is a slave completely under the dominion of another, with no powers of any sort, and another a free man, who is gifted in every way, and is most generous in bestowing out of his opulent wealth (material as well as intangible), privately and publicly, without let or hindrance; for he is his own master and owes no account to anyone.
The first is like the imaginary gods which men set up—whether powers of nature, which have no independent existence but are manifestations of Allah, or deified heroes or men, who can do nothing of their own authority but are subject to the Will and Power of Allah; the second describes in a faint way the position of Allah, the Self Subsistent, to Whom
belongs the dominion of all that is in heaven and earth, and Who bestows freely of His gifts on all His creatures.” (The Meaning of The Noble Qur’an by Abdullah Yusuf Ali, page 176 – 177, online source http://www.ulc.org/wp-content/uploads/2012/10/English-Quran-With-Commentaries.pdf )
Dr. Muhammed Asad:
“84 I.e., “DO NOT BLASPHEME AGAINST GOD BY REGARDING ANYONE OR ANYTHING AS COMPARABLE WITH HIM, OR BY TRYING TO DEFINE HIM IN ANY TERMS WHATSOEVER” – since “definition” is, in the last resort, equivalent to a delimitation of the qualities of the object thus to be defined in relation to, or in comparison with, another object or objects: God, however, is “sublimely exalted above anything that men may devise by way of definition” (see last sentence of 6:100, and the corresponding note 88).
85 The obvious answer is that they cannot. The implication is equally clear: if even these two kinds of man cannot be deemed equal, HOW COULD ANY CREATED BEING, WITH ITS INTRINSIC, UTTER DEPENDENCE ON OTHER CREATED BEINGS, OR ANY FORCE OF NATURE CONCEIVABLE OR IMAGINABLE BY MAN, BE THOUGHT OF AS POSSESSING POWERS COMPARABLE WITH THOSE OF GOD, who is almighty, limitless, unconceivable – the self-sufficient fount of all that exists?
(This argument is continued and further elaborated in the subsequent parable.) (The Message of The Quran translated and explained by Muhammad Asad, page 578 – 579, online source http://www.usc.edu/schools/college/crcc/private/cmje/religious_text/The_Message_of_The_Quran__by_Muhammad_Asad )
Maulana Muhammad Ali:
“75a. BY SLAVE IS MEANT THE IDOL-WORSHIPPER WHO, INSTEAD OF BEING MASTER OF IDOLS, STONES, AND SUCH-LIKE OBJECTS, AS ALLAH HAS CREATED HIM TO BE, CHOOSES TO BECOME A SLAVE TO THEM, bows before them, and considers them more powerful than himself.
By the master of the goodly provision from Allah is meant the recipient of the Divine revelation, i.e., the Prophet. The comparison is introduced to show that the idol-worshippers will ultimately find themselves deprived of all power.
The words of the PARABLE find an echo in the reply of Ab∂ Sufyan, when the Holy Prophet, who was entering Makkah as a conqueror, inquired of him: “Has not the time come when thou shouldst know that there is no god but Allah?”
Abu Sufyan replied: ‘By Allah! I am now certain that if there had been a god besides Allah, it would surely have availed me somewhat’.” (The Holy Quran Arabic Text with English Translation, Commentary and comprehensive Introduction [Year 2002 Edition] by Maulana Muhammad Ali, page 549)
Malik Ghulam Farid:
“1562. The disbelievers are like a person who has lost all freedom of will and action and is the slave of his own low desires and fancies.
1563. The implied references may be to the Holy Prophet – God’s servant par excellence. (1) He served mankind secretly (by praying for them at night) and openly (by tangible acts of service). (2) He served mankind at all hours of the day and night.” (The Holy Qur’an – Arabic Text With English Translation & Short Commentary By Malik Ghulam Farid, page 533 – 534)
“66 IN THE PRECEDING VERSE, THE MUSHRIKS WERE TOLD NOT TO MAKE COMPARISONS BETWEEN ALLAH AND HIS CREATURES, for there is nothing like Him. As the bases of their comparison were wrong, their conclusions were also misleading. In this verse appropriate similitudes have been cited and right comparisons have been made to lead them to Reality.
67 Between the last question and “May God be praised! “There is a gap which is to be filled with the help of the latter. When the question was posed, obviously the mushriks (polytheists) could not say that the two men were equal. So some of them would have admitted that they were not equal, while the others would have kept quiet for fear that in case of admission, they would have to abide by its logical conclusion, that is, the admission of REFUTATION OF THE DOCTRINE OF SHIRK (POLYTHEISM).
Therefore, the words, “May God be praised!” have been put in the mouth of the Prophet in answer to both kinds of the response to the question. In the first case, it would mean: “May God be praised! you have admitted at least so much”. In the second case, it would mean: “May God be praised! you have kept quiet in spite of all your obduracy and have not had the audacity to say that both were equal.”
68″…most people do not understand (this simple thing)” that while they feel and carefully observe the distinction between those who have powers and those who are powerless, they neither feel nor OBSERVE THE CLEAR DISTINCTION BETWEEN THE CREATOR AND HIS CREATION.
That is why they associate the creatures with the Creator in His Attributes and Powers and show the kind of allegiance to them as is the exclusive right of the Creator. The pity is that in their everyday life, they would beg for sane thing from the master of the house and not from the servants.
But in contrast to this, they would beg for their needs from the servants of Allah and not from Him.” (Sayyid Abul Ala Maududi – Tafhim al-Qur’an – The Meaning of the Qur’an – online source http://www.englishtafsir.com/Quran/16/index.html#sdfootnote67sym )
Fi Dhilal Al Qur’an – Qutb:
“The surah then gives two examples of a master who can give and provide and a disabled slave who earns nothing. THESE EXAMPLES ARE GIVEN TO BRING THE ETERNAL TRUTH THEY HAD OVERLOOKED CLOSER TO THEIR UNDERSTANDING. THAT TRUTH IS THAT GOD HAS NO PEERS AND THAT THEY MUST NEVER EQUATE GOD WITH ANYONE IN THEIR WORSHIP.
Everyone and everything other than God is created by Him, and all are His servants. God makes this comparison between a man enslaved, unable to do anything of his own accord, and a [free] man on whom We have bestowed goodly favours, and he gives of it both in private and in public. Can these two be equal? All praise is to God alone, but most people have no knowledge.
And God makes another comparison between two men, one of whom is dumb and can do nothing of his own accord. He is a sheer burden to his master: wherever he sends him, he accomplishes no good. Can he be considered equal to one who enjoins justice and follows a straight path? (Verses 75-76) The first example is taken from their own lives.
They had slaves who owned nothing and who had no power over anything. They would never put the slave who has no independent will on the same level as his master who enjoys considerable power. How then can they justify their equation of the Master and Owner of all with any of His creation, when they all serve Him?
The second example depicts a dumb, dull and weak person who understands nothing and can do no good, and another who is eloquent, able, encouraging fairness, hard working for every good cause. No reasonable person would equate the two.
How is it, then, that dumb idols of stone are equated with God Almighty, who enjoins only what is reasonable and guides to the path of truth? With these two examples we come to the end of this passage which started with God’s order that people must not worship two deities. It ends with amazement at the attitude of those who attribute Godhead to other deities.
God has replaced Joseph’s trials with his new position of power, and also with the promise of better things to come in the life to come. All this reward is for faith, righteousness and perseverance in the face of difficulty.” (In The Shade Of The Quran (‘Fi Dhilal Al Qur’an’), by Sayyid Qutb volume 11, page 52)
Maulana Abdul Majid Daryabadi:
“265. (TO ILLUSTRATE THE UTTER UNWORTHINESS OF POLYTHEISM).
266. Equally contemptible are the gods; far from owning anything, they are themselves owned by others.
267. The verb implying the pronoun here, is not dual but plural, which signifies that not two individuals but two classes of persons are meant.
268. i.e., of mankind.” (Tafsir-Ul-Qur’an – Translation and Commentary Of The Holy Qur’an [Published By Darul Ishaat Urdu Bazaar Karachi: Pakistan] by Maulana Abdul Majid Daryabadi, volume 2, page 418)
Tafsir Ibn Kathir:
“The Example of the Believer and the Disbeliever, or the Idol and the True God
Al-`Awfi reported that Ibn `Abbas said: “This is the example which Allah gives of the disbeliever and the believer.” This was also the view of Qatadah and Ibn Jarir.
The servant who has no power over anything is like the disbeliever, and the one who is given good provisions and spends of them secretly and openly is like the believer. Ibn Abi Najih reported that Mujahid said:
“This is an example given of the IDOL AND THE TRUE GOD – CAN THEY BE THE SAME” Once the difference between them is so clear and so obvious, no one can be unaware of it except the one who is foolish. Allah says: (All the praises and thanks are to Allah. Nay! (But) most of them know not.) (Tafsir Ibn Kathir on Surah 16:75 – Online source http://www.alim.org/library/quran/AlQuran-tafsir/TIK/16/75 )
 Illuminating Discourses on the Noble Quran – Tafseer Anwarul Bayan – by Shaykh Ashiq Ilahi Madni volume 3, page 175