Muwatta Malik 164
Prayer
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَرْفَعُ يَدَيْهِ فِي الصَّلاَةِ .
Yahya related to me from Malik from Yahya ibn Sa'id from Sulayman ibn Yasar that the Messenger of Allah, may Allah bless him and grant him peace, used to raise his hands in the prayer
Grading: Salim al-Hilali: Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.