Hadith #1652The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day · Narrated by Abu Ishaq al-Sabay'ai' أبو إسحاق السبيعي عمرو بن عبد الله, Aisha bint Abi Bakr, al-Aswad bin Yazid الأسود بن يزيد بن قيس النخعي, Amr bin 'Ali bin Bahr al-Bahli عمرو بن علي بن بحر الباهلي, Umar bin Abi Za'id'h عمر بن أبي زائدة الهمداني
“The Messenger of Allah (ﷺ) used to pray standing and sitting. If he started to pray standing, he would bow standing and if he started to pray sitting, he would bow sitting.”