ALLAH SWT say's:

ALLAH SWT say's

They conceal within their souls what they would not reveal to you. They say: Had we any hand in the affair, we would not have been slain here [in a Jihad battle]. Say: Had you remained in your houses, those for whom slaughter was ordained [in a Jihad battle] would certainly have gone forth to the places where they would be slain, and that Allah might test what was in your breasts and that He might purge what was in your hearts; and Allah knows what is in the breasts.
Quran [3.155]

(As for) those of you who turned back on the day when the two armies met, only the Satan sought to cause them to make a slip on account of some deeds they had done, and certainly Allah has pardoned them; surely Allah is Forgiving, Forbearing.
Quran [3.156]