A group of people will appear among you whose prayer, fasting and deeds will make you think little of your own prayer, fasting and deeds. They will recite the Qur'an, but it wil not get past their throats, and they will pass through the deen like an arrow passes through game. You look at the arrowhead, and you see nothing, and you look at the shaft, and you see nothing, and you look at the flights, and you see nothing. And you are in doubt about the notch.

Malik :: Book 15 : Hadith 15.4.10