Musnad Abu Ya'la al-Mawsili 42:436

Sufyan ibn Waki' narrated to us, my father narrated to us, from Ubaydullah ibn Abi Humayd, from Abu Mulayh, he said: Abu Sa'id al-Khudri narrated to me, he said: I heard the Messenger of Allah (may Allah bless him and grant him peace) saying: "When one of you completes his prayer, then returns to his house, let him pray, and let him assign a portion of his prayer to his house; for indeed, Allah will make from his prayer in his house goodness."