Quran 9:94 — Ultimatum (Bara'ah)

They apologize to you when you return to them (from battle). Say, "Do not apologize; we no longer trust you. GOD has informed us about you." GOD will see your works, and so will the messenger, then you will be returned to the Knower of all secrets and declarations, then He will inform you of everything you had done.

[9:93] The blame is on those who ask your permission to stay behind, even though they have no excuse. They have chosen to be with the sedentary. Consequently, GOD has sealed their hearts, and thus, they do not attain any knowledge.

[9:95] They will swear by GOD to you, when you return to them, that you may disregard them. Do disregard them. They are polluted, and their destiny is Hell, as a requital for the sins they have earned.