The Messenger of Allah ﷺ said, "I have been commanded to perform the two units of the forenoon prayer and the witr, though they were not made obligatory."
حدثنا وكيع عن إسرائيل عن جابر عن عكرمة
قال رسول الله ﷺ أمرت بركعتي الضحى وبالوتر ولم يكتب
No references are available.
Its isnad is daif due to the weakness of Jabir Jafi. The hadith is abridged from 2050. In Nasb Raya 2:115, he indicated that Hakim narrated it through this route, but I did not find it in Mustadrak. It will come up again at 2081, 2918, and 2919.