Abu Murra, the freed slave of Umm Hani, narrated on the authority of Abu Darda':My Friend (ﷺ) instructed me in three (acts), and I would never abandon them as long as I live. (And these three things are): Three fasts during every month, the forenoon prayer, and this that I should not sleep till I have observed the Witr prayer

English translation · Sahih Muslim