The Messenger of Allah ﷺ said, "Yawning is from Satan, so when one of you yawns, let him suppress it as much as he can."
أن رسول الله ﷺ قال: التثاؤب من الشيطان، فإذا تثاءب أحدكم فليكظم ما استطاع.
Muslim narrated it in Zuhd (2994) through multiple routes from Ismail bin Jafar, from Ala, from his father, from Abu Hurairah, who mentioned it.