Al-Ahzab (33): Verses 20-21
They think the confederates [are a great force]...
Their state is one of extreme cowardice. When the enemy forces were approaching, they feared them. When they arrived, they wished they were out in the deserts, not among the fighters.
Furthermore, when they were present, they were as if absent, because they did not fight, just as Allah the Exalted said:
{And if they were among you, they would fight little.} (Quran 33:20b)
And when the believers saw the confederates, they said, "This is what Allah and His Messenger had promised us, and Allah and His Messenger spoke the truth." And it only increased them in faith and submission.
When the believers saw the confederate armies, they said, "This is precisely what Allah and His Messenger had promised us [regarding the trial of the battle of the Trench/Ahzab]." And Allah and His Messenger spoke the truth. This realization did nothing but increase them in faith (īmān) and submission (taslīm).