The word(s) "faithlessness" appears 1 time(s) in 1 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) And remember We took your covenant and We raised above you (the towering height) of Mount (Sinai): (Saying): "Hold firmly to what We have given you, and hearken (to the Law)": They said:" We hear, and we disobey:" And they had to drink into their hearts (of the taint) of the calf because of their faithlessness. Say: "Vile indeed are the behests of your Faith if ye have any faith!"