Umm al-Mu'mineen Sayyidah Aisha (may Allah be pleased with her) narrated that when the Messenger of Allah (peace and blessings be upon him) wished to perform the Tahajjud prayer sitting, he would recite while sitting. When about thirty or forty verses remained, he would stand up and recite them standing, then perform bowing (ruku') and prostration (sujud). In the second rak'ah, he would do the same. After finishing the prayer, if he saw that I was awake, he would talk to me, but if I was asleep, he would also lie down.
Hadith Referenceاللؤلؤ والمرجان / كتاب صلاة المسافرين وقصرها / 425
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 18 كتاب تقصير الصلاة: 20 باب: إذا صلى قاعدا ثم صح أو وجد خفة تمّم ما بَقِي»