Musnad Ahmad 1156:259

Muhammad ibn Ja‘far narrated to us, he said: Shu‘bah narrated to us, from Musa ibn Abi ‘Aishah, from a freed slave of Umm Salamah, from Umm Salamah, that the Messenger of Allah (may Allah bless him and grant him peace) used to say when he prayed the morning prayer, when he would say the taslim: "O Allah, I ask You for beneficial knowledge, and goodly provision, and accepted deeds."