Sahih al-Bukhari 5058

Narrated Abu Sa`id Al-Khudri:I heard Allah's Messenger (ﷺ) saying, "There will appear some people among you whose prayer will make you look down upon yours, and whose fasting will make you look down upon yours, but they will recite the Qur'an which will not exceed their throats (they will not act on it) and they will go out of Islam as an arrow goes out through the game whereupon the archer would examine the arrowhead but see nothing, and look at the unfeathered arrow but see nothing, and look at the arrow feathers but see nothing, and finally he suspects to find something in the lower part of the arrow