Sayyidah Aishah (may Allah be pleased with her) said that the Prophet (peace and blessings be upon him) would sleep; when he woke up, he would use the tooth-stick (miswak) and perform ablution (wudu). Then he would pray eight rak'ahs, sitting after every two rak'ahs and saying the salam. Then he would pray five rak'ahs, sitting only in the fifth rak'ah and saying the salam only in the fifth rak'ah.
(b) In the narration of Muhammad bin Ja'far bin al-Zubayr the wording is that he (peace and blessings be upon him) would pray six rak'ahs, two at a time.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4801