It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that my beloved friend (peace be upon him) advised me regarding three things (which I will not leave until my death): to perform the Witr prayer before sleeping, to fast three days in every month, and to take a bath on Friday.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 7138
Hadith Gradingحکم دارالسلام:حسن، خ: 1178، م: 721، فيه تدليس الحسن، وقد توبع .