Riyad as-Salihin 15:19

'Aishah (May Allah be pleased with her) reported:

The Messenger of Allah (ﷺ) used to recite in his bowing and prostration: "Subbuhun Quddusun, Rabbul-mala'ikati war-ruh [You are the Most Glorious. The Most Holy. You the Rubb of the angels and of Jibril