It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) used to pray 13 rak‘ahs at night (eight of Tahajjud, three of Witr, and two Sunnahs of Fajr).
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2019