Amir al-Sha'bi (may Allah have mercy on him) said: I asked Sayyiduna Abdullah bin Abbas and Sayyiduna Abdullah bin Umar (may Allah be pleased with them): How was the night prayer of the Messenger of Allah (peace and blessings be upon him)? They both said: "Thirteen rak'ahs: eight rak'ahs (of tahajjud), then he would pray three rak'ahs of witr, and two rak'ahs after Fajr."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12515