Abu Umama told of his hearing Allah's Messenger ﷺ say, “If anyone goes to bed in a state of purity and makes mention of Allah till drowsiness overtakes him, he will not turn round at any time during the night and ask Allah at that time for some of the good of this world and the next without His giving it to him.” Nawawi mentioned it in Kitab al-adhkar by the transmission of Ibn as-Sunni.