Quran 9:46 — Ultimatum (Bara'ah)

Had they really wanted to mobilize, they would have prepared for it thoroughly. But GOD disliked their participation, so He discouraged them; they were told, "Stay behind with those who are staying behind."

[9:45] The only people who wish to be excused are those who do not really believe in GOD and the Last Day. Their hearts are full of doubt, and their doubts cause them to waver.

[9:47] Had they mobilized with you, they would have created confusion, and would have caused disputes and divisions among you. Some of you were apt to listen to them. GOD is fully aware of the transgressors.