Now let us turn to the explanation of these verses:
1. Verse 121 begins with the words, وَإِذْ غَدَوْتَ مِنْ أَهْلِكَ (When you left your house in the morning in order to place the believers in positions for fighting)
This is an example of the miraculous style of the Holy Qur'an, specially when it reports events. It does not describe any event in its total detail as a matter of general principle. Events, or their details are taken up only when they carry with them implied points of guidance. For instance, a particular secondary detail, such as the time of leaving the house, has been identified through the word غَدَوْتَ ('ghadawta'); and hadith narrations prove that this morning was that of the seventh of Shawwal, Hijrah year 3.
Then comes the description of the point from where this expedition started. The word مِنْ أَهْلِكَ indicates that the Holy Prophet (SM) was with his family at that time and when the time came to leave, he left, leaving his family behind him, even though this attack was aimed at Madinah. These secondary details have guidance built in them. When there is the command of Allah, it is expected that the love of family and home should not stop one from obeying it. It will be noticed that details of what happened between the period of leaving the house and reaching the war front remain undescribed. Instead, the first thing done on the war front has been described as تُبَوِّئُ الْمُؤْمِنِينَ مَقَاعِدَ لِلْقِتَالِ the placing of believers in position3 for fighting.
The verse ends with the words, وَاللَّهُ سَمِيعٌ عَلِيمٌ (And Allah is All-Hearing, All-Knowing). By reminding Muslims of these attributes of Allah, it has been pointed out that everything said by the two parties at that time was all in the knowledge of Allah Almighty. and absolutely nothing of what happened to the two of them remains hidden from Him, and so shall it be with the end of the war; that too, is not hidden from Him.
Next comes verses 122 beginning with the words إِذْ هَمَّت طَّائِفَتَانِ مِنكُمْ أَن تَفْشَلَا (When two of your groups tended to lose heart while Allah was their guardian). These 'two groups' refer to the Bani Hirithah of the tribe of Aws and Bani Salamah of the tribe of Khazraj. These 'two groups' lost the courage to fight when they saw the hypocrite, 'Abdullah ibn Ubayy and his men breaking away. But, Allah, in his grace, helped them come out of this state of apprehensiveness. Here, the fact was that their weakness was caused by the thought, and certainly not because of any weakness in faith. Ibn Hisham, the famous historian of Muslim battles has made this very clear. Then, the very Qur7anic statement, وَاللَّهُ وَلِيُّهُمَا (while Allah was their guardian) is a testimony to their perfect faith. Therefore, some elders from these two tribes used to say: "No doubt, the verse contains a complaint against us, but at the same time it bears a good news for us in the words: وَاللَّهُ وَلِيُّهُمَا (While Allah was their guardian).