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." (Using translation from Tirmidhī 2747)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ اللهَ ﷻيُحِبُّ الْعُطَاسَ وَيَكْرَهُ التَّثَاؤُبَ فَمَنْ عَطَسَ فَحَمِدَ اللهَ فَحَقٌّ عَلَى مَنْ سَمِعَهُ أَنْ يَقُولَ يَرْحَمُكَ اللهُ وَإِذَا تَثَاءَبَ أَحَدُكُمْ فَلْيَرْدُدْهُ مَا اسْتَطَاعَ وَلَا يَقُلْ آهْ آهْ فَإِنَّ أَحَدَكُمْ إِذَا فَتَحَ فَاهُ فَإِنَّ الشَّيْطَانَ يَضْحَكُ مِنْهُ أَوْ بِهِ قَالَ حَجَّاجٌ فِي حَدِيثِهِ وَأَمَّا التَّثَاؤُبُ فَإِنَّمَا هُوَ مِنَ الشَّيْطَانِ