Majma al-Zawaid — Hadith 3666

Yusuf bin Abdullah bin Salam narrates: I stayed with Sayyiduna Abu al-Darda' (may Allah be pleased with him) in order to keep learning from him. When the time of his death drew near, he said: "Inform the people that I am about to die." So I informed the people. When I came back, the house was full and there were people outside too. I said: "I have informed the people that you are about to die, and the house and the outside are filled with people." He said: "Take me out." So we brought him out. Then he said: "Sit me up." So we sat him up. He said: "O people! I heard the Prophet (peace and blessings be upon him) say: 'Whoever performs ablution and does it thoroughly, then prays two complete rak'ahs, Allah Almighty will give him whatever he asks of Him, either soon or later.'" Sayyiduna Abu al-Darda' (may Allah be pleased with him) said: "O people! Beware of turning this way and that during prayer, for the one who turns this way and that has no prayer. If you are compelled to do so, let it be in voluntary prayer; do not do it in the obligatory prayer."
Ahmad and al-Tabarani in al-Mu'jam al-Kabir recorded it. Its chain contains a narrator, Maymun Abu Muhammad; al-Dhahabi says: He is not known.