Sunan At-Tirmidhi

Narrated Abu Hurairah:that the Messenger of Allah (ﷺ) said: ""Indeed Allah loves sneezing and He dislikes the yawn. So when one of you sneezes and says 'Al-Hamdulillah (All praise is due to Allah),' then it is a right due from every one who hears him to say: 'Yarhamukallah (May Allah have mercy upon you)' As for yawning then when one of you yawns let him suppress it as much as possible and not say: ""Hah Hah' for that is only from Ash-Shaitan laughing at him