Musnad Ahmad 30:2886

Waki’ narrated to us, al-A’mash narrated to us, from Abu Salih, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Would one of you like, when he returns to his family, to find three large, fat, pregnant she-camels? For three verses that one of you recites in his prayer are better for him than three large, fat, pregnant she-camels." He said: "Indeed, the most burdensome prayers for the hypocrites are the Isha prayer and the Fajr prayer, and if they knew what was in them, they would have come to them even if by crawling."