The word(s) "weak-hearted" appears 3 time(s) in 3 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) And how many a prophet has fought with whom were many worshippers of the Lord; so they did not become weak-hearted on account of what befell them in Allah's way, nor did they weaken, nor did they abase themselves; and Allah loves the patient.

(2) And certainly Allah made good to you His promise when you slew them by His permission, until when you became weak-hearted and disputed about the affair and disobeyed after He had shown you that which you loved; of you were some who desired this world and of you were some who desired the hereafter; then He turned you away from them that He might try you; and He has certainly pardoned you, and Allah is Gracious to the believers.

(3) When Allah showed them to you in your dream as few; and if He had shown them to you as many you would certainly have become weak-hearted and you would have disputed about the matter, but Allah saved (you); surely He is the Knower of what is in the breasts.