Scholars on the ‘invasion’ of Sawiq.
Shaykh Allamah Shibli Nomani:
“Abu Sufyan was now the chief of the Quraish, and as such his first duty was to be revenged for Badr. On the return of the Quraish from Badr, he took a vow never to dress his hair with oil and never to take an ablutionary bath, until he had taken his revenge for those who had fallen.
Consequently at the head of two hundred camel riders he advanced towards Medina, confident of help from the Jews against the Muslims. First he approached Huyayy Ibn Akhtab; but Huyayy did not even open the door of his house. Then he came to Salam Ibn Mishkam, the chief of the Bani Nadir, who was also the treasurer of the business investments of the Jews.
He extended to Abu Sufyan a warm welcome, entertained him with sumptuous feasts and wines, and acquainted him with the secrets of Medina. In the morning Abu Sufyan attacked Arid, that lay three miles from Medina, killed an Ansari named Sa’d Ibn Amr and set on fire a few houses and stocks of hay.
By so doing, he thought, he had absolved himself from his vow. The news was brought to the Prophet (p) who set out in pursuit for provisions Abu Sufyan had nothing but ‘Sawiq,’ which, as he fled with mind upset, he dropped down in bagfuls, and the Muslims picked them up. Sawiq is the Arabic word for Indian ‘Sallu’ and hence the engagement is known as Ghazwa Sawiq.” 
Hajjah Amina Adil:
“THE RAID OF SAWIQ
In the month of Dhul-Qa’da the Raid of Sawiq occurred, and it came about in the following way:
Abu Sufyan had a son by the name of Amr who had been taken prisoner. Abu Sufyan was constantly saying, ‘
‘If only I had been along at the Battle of Badr, then I would have acted in such a way and ealt with them in such a way…’
The people of Mecca grew tired of hearing this and said to him,
‘So, go now and do it!’
One man called Hamid came to Abu Sufyan said,
‘By God, I will go and kill Muhammad and, if it is made easy, I will destroy his whole house and family.’
So Abu Sufyan quickly made ready two-hundred riders and they set out for Madinah. When they approached the town, they stopped and stayed with the Bani Nadir who sent fifty more men with them.
They came to a field where there were to Muslims of the Ansar working, and they killed them. Then they set fire to a place outside of the city. News of all this reached the Holy Prophet, and he speedily rose to pursue Abu Sufyan. Abu Sufyan fled at great speed, taking three stages in one day.
The Holy Prophet could not catch up with him. Abu Sufyan’s flight was such that whoever had provisions in his travelling pack threw them all by the wayside in his haste. Therefore, this raid was called the Raid of Sawiq and it took place in the month of Dhul’Qa’da, because it was followed by the month of Dhul’Hijja.
The Holy Prophet sacrificed two sheep and called the Muslims to the sacrifice, ordering them to sacrifice as well. This was the first Id-al-Adha in Islam. The Prophet slaughtered the sheep by his own hand, one for himself, and one for those of his nation who were unable to slaughter.” 
Bashir Aḥmad M.A.:
“GHAZWAH OF SAWIQ – DHUL-HIJJAH 2 A.H.
The mourning which rippled through Makkah as a result of the Battle of Badr has already been described. Almost all the chieftains of the Quraish had been slain, and now the rule of Madinah had come to the lot of Abu Sufyan bin Ḥarb.
After Badr he vowed that until he had sought revenge for those who had fallen at Badr, he would abstain from having relations with his wife and applying oil to his hair.
As such, a few months after Badr, in the month of Dhul-Hijjah, Abu Sufyan set out from Makkah with a force of twohundred armed men from the Quraish and reached a place close to Madinah via the route of Najd.
Upon reaching there, he left his army at some distance from Madinah and in the veil of the darkness of night, reached the abode of Ḥuyayy bin Akhṭab, who was chief of the Jewish tribe, the Banu Nadir, and sought his aid.
However, since Ḥuyayy still somewhat remembered his treaty and agreement, he refused. Then, in the same manner, Abu Sufyan secretly went to the home of another chief of the Banu Nadir named Salam bin Mashkam, and sought his support against the Muslims.
This wretched man, however, very audaciously ignored all of his treaties and agreements and warmly welcomed Abu Sufyan as a guest for the night, and transmitted secret intelligence to him pertaining to the Muslims.
Before dawn, Abu Sufyan took leave and upon reaching his army, dispatched a contingent of the Quraish to raid a valley named ‘Arīḍ, which was located close to Madinah. This was a valley where the animals belonging to the Muslims would graze, and which was situated at a distance of only three miles from Madinah. It is likely that Abu Sufyan was made aware of this through Salām bin Mashkam.
When this contingent of the Quraish reached the valley of ‘Arid, fortunately, at the time, the animals belonging to the Muslims were not present. Albeit, a Muslim from among the Ansar and a companion of his were present at the time.
The Quraish apprehended both of them and ruthlessly murdered them. Then, they set ablaze the date palms in the area and set fire to the homes and small huts which were located there, before returning to the camp of Abu Sufyan. Considering this success as being sufficient fulfillment of his vow, Abu S
ufyan ordered the army to return. On the other hand, when the Holy Prophet was informed of the attack made by Abu Sufyan, he set out with a group of Companions in his pursuit. However, since Abu Sufyan did not fancy throwing the fulfillment of his vow to doubt, he fled so frantically that the Muslim army was unable to apprehend him.
Ultimately, after an absence of a few days, the Holy Prophet returned to Madinah. This Ghazwah is known as the Ghazwah of Sawiq because when Abu Sufyan made haste to Makkah, he fled leaving his ration behind, which primarily consisted of ‘Sawiq’ or sacks of barley, partly due to anxiety and also in order to lighten his load.” 
 Sirat -un- Nabi [Sallallahu Alaihi Wasallam] By Shaykh Allamah Shibli Nomani (r.a) – Volume 2, Page 54
 Muhammad, the Messenger of Islam: His Life & Prophecy by Hajjah Amina Adil, page 309 – 310
 The Life & Character of the Seal of Prophets (May Peace and Blessings of Allah be upon him) (Sirat Khatamun-Nabiyyin) By Mirza Bashir Aḥmad M.A., volume 2, page 279 – 80