These verses were revealed in Madinah (Abdullah Ibn Abbas). 
64:14 O you who have believed, indeed, among your wives and your children are enemies to you, so beware of them. But if you pardon and overlook and forgive – then indeed, God is Forgiving and Merciful.
64:15 Your wealth and your children are but a trial, and God has with Him a great reward.
64:16 So fear Allah as much as you are able and listen and obey and spend [in the way of God]; it is better for your selves. And whoever is protected from the stinginess of his soul – it is those who will be the successful.
Sometimes a believer gets tested through trials by their partner’s or their children in disobeying God’s commands. Instead of the believer doing good deeds, their family members tempt him (or her) to go on to the wrong path in committing sins (Asbab Al-Nuzul by Al-Wahidi, Tafsir al-Jalalayn and Tafsir Ibn kathir).
“Your wives and your children are enemies to you”, is used here in the sense that the family will sometimes direct a righteous human being to disobey God. The man, here who loves his family would obey them over God and indulge in sinning.
Dr. Muhammad Asad:
“11 I.e., “sometimes, your spouses…”, etc. Since, in the teachings of the Qur’an, all moral duties are binding on women as well as on men, it is obvious that the term azwajikum must not be rendered as “your wives”, but is to be understood – according to classical Arabic usage – as applying equally to both the male and the female partners in a marriage.
12 Love of his or her family may sometimes tempt a believer to act contrary to the demands of conscience and faith; and, occasionally, one or another of the loved ones – whether wife or husband or child – may consciously try to induce the person concerned to abandon some of his or her moral commitments in order to satisfy some real or imaginary “family interest”, and thus becomes the other’s spiritual “enemy”. It is to this latter eventuality that the next sentence alludes.” 
Tafsir al-Jalalayn (15/16th century commentary):
“O you who believe! Indeed among your wives and children there are enemies for you, so beware of them, of obeying them in neglecting [the performance of] good [deeds], such as struggling or emigrating — because the reason why this verse was revealed was [precisely their] obedience [of them] in such [matters].
And if you pardon, them, for their impeding you from such good [deeds], justifying it on account of the distress that parting with you causes them, and overlook [such enmity] and forgive, then assuredly God is Forgiving, Merciful.” (Tafsir al-Jalalayn on Surah 64:14 – Online Source)
Scholar Abdullah Yusuf Ali:
“5494 In some cases the demand of families, i.e., wife and children may conflict with a man’s moral and spiritual convictions and duties. In such cases he must guard against the abandonment of his convictions, duties, and ideals to their requests or desires. But he must not treat them harshly.
He must make reasonable provision for them, and if they persist in opposing his clear duties and convictions, he must forgive them and not expose them to shame or ridicule, while at the same time holding on to his clear duty.
Such cases occurred when godly men undertook exile from their native city of Makkah to follow the Faith in Madinah. In some cases their families murmured, but all came right in the end.
5495 For the different words for ‘forgiveness’ see. N.110 to 2:109.
5496 Children may be a trial in many senses:
(1) their different ways of looking at things may cause you to reflect, and to turn to the highest things of eternal importance;
(2) their relationship with you and with each other may confront you with problems far more complicated than those in separate individual lives, and thus become a test of your own strength of character and sense of responsibility;
(3) their conflict with your ideals (see n. 5494 above) may vex your spirit, but may at the same time search out your fidelity to Allah; and
(4) their affection for you and your affection for them, may be a source of strength for you if it is pure, just as it may be a danger if it is based on selfish or unworthy motives. So also riches and worldly goods have their advantages as well as dangers.
5497 Fear Allah combined with as much as you can obviously means: ‘lead lives of self-restraint and righteousness’: the usual meaning of Taqwa: see n. 26 to 2:2.
5498 Charity is meant to help and do good to other people who need it. But it has the highest subjective value for the person who gives it. Like mercy ‘it blesseth him that gives and him that takes’. It purifies the giver’s soul: the affection that he pours out is for his own spiritual benefit and progress. Cf. Coleride: ‘He prayeth best who loveth all things both great and small, for the Great God Who Loveth us, Who made and loveth all’.
5499 Cf. 59:9. Our worst enemy is within ourselves the grasping selfishness which would deprive others of their just rights or seize things which do not properly belong to it. If we can get over this covetous selfishness, we achieve real Prosperity in justice and truth.” 
Maulana Muhammad Ali:
“14a. Because it is most often for the sake of one’s wife and children that one acts wrongfully towards others. Thus, in some cases the wife or the children become an enemy to man. Note the use of the word min (“of”), which shows that it is only occasionally that a man is led to an evil course.” 
 Sayyid Abul Ala Maududi:
“Muqatil and Kalbi say that it was partly revealed at Makkah and partly at Madinah. Hadrat Abdullah bin Abbas and Ata bin Yasar say that vv. 1-13 were revealed at Makkah and vv. 14-18 at Madinah. But the majority of commentators regard the whole of the surah as a Madinan Revelation.
Although there is no internal evidence to help determine its exact period of revelation, yet a study of its subject matter shows that it might probably have been sent down at an early stage at Madinah. That is why it partly resembles the Makkah surahs and partly the Madinan Surahs.” (Sayyid Abul Ala Maududi – Tafhim al-Qur’an – The Meaning of the Qur’an – Online source)
 The Message of The Quran translated and explained by Muhammad Asad, Page 1180
 The Meaning Of the Glorious Qur’an: Text, Translation, and Commentary by Abdullah Yusuf Ali, page 405
 The Holy Quran Arabic Text with English Translation, Commentary and comprehensive Introduction by Maulana Muhammad Ali, Page 1099