Muwatta Imam Malik Book of Prayer, Hadith 19
Yahya related to me from Malik from Yahya ibn Sa'id from Sulayman ibn Yasar that the Messenger of Allah ﷺ used to raise his hands in the prayer.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَرْفَعُ يَدَيْهِ فِي الصَّلاَةِ .