The Prophet ﷺ said, "Allah likes sneezing and dislikes yawning, so if someone sneezes and then praises Allah, then it is obligatory on every Muslim who heard him, to say: May Allah be merciful to you (Yar-hamuka-l-lah). But as regards yawning, it is from Satan, so one must try one's best to stop it, if one says 'Ha' when yawning, Satan will laugh at him."  

عَنِ النَّبِيِّ ﷺ إِنَّ اللَّهَ يُحِبُّ الْعُطَاسَ وَيَكْرَهُ التَّثَاؤُبَ فَإِذَا عَطَسَ فَحَمِدَ اللَّهَ فَحَقٌّ عَلَى كُلِّ مُسْلِمٍ سَمِعَهُ أَنْ يُشَمِّتَهُ وَأَمَّا التَّثَاوُبُ فَإِنَّمَا هُوَ مِنَ الشَّيْطَانِ فَلْيَرُدَّهُ مَا اسْتَطَاعَ فَإِذَا قَالَ هَا ضَحِكَ مِنْهُ الشَّيْطَانُ  

The Prophet ﷺ said, "Allah loves sneezing but dislikes yawning; so if anyone of you sneezes and then praises Allah, every Muslim who hears him (praising Allah) has to say Tashmit to him. But as regards yawning, it is from Satan, so if one of you yawns, he should try his best to stop it, for when anyone of you yawns, Satan laughs at him."  

عَنِ النَّبِيِّ ﷺ قَالَ إِنَّ اللَّهَ يُحِبُّ الْعُطَاسَ وَيَكْرَهُ التَّثَاؤُبَ فَإِذَا عَطَسَ أَحَدُكُمْ وَحَمِدَ اللَّهَ كَانَ حَقًّا عَلَى كُلِّ مُسْلِمٍ سَمِعَهُ أَنْ يَقُولَ لَهُ يَرْحَمُكَ اللَّهُ وَأَمَّا التَّثَاؤُبُ فَإِنَّمَا هُوَ مِنَ الشَّيْطَانِ فَإِذَا تَثَاوَبَ أَحَدُكُمْ فَلْيَرُدَّهُ مَا اسْتَطَاعَ فَإِنَّ أَحَدَكُمْ إِذَا تَثَاءَبَ ضَحِكَ مِنْهُ الشَّيْطَانُ  

Allah likes sneezing but dislikes yawning. So when one of you yawns, he should restrain it as much as possible, and should not say Ha, Ha, for that is from the devil who laughs at him.  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ يُحِبُّ الْعُطَاسَ وَيَكْرَهُ التَّثَاؤُبَ فَإِذَا تَثَاءَبَ أَحَدُكُمْ فَلْيَرُدَّهُ مَا اسْتَطَاعَ وَلاَ يَقُلْ هَاهْ هَاهْ فَإِنَّمَا ذَلِكُمْ مِنَ الشَّيْطَانِ يَضْحَكُ مِنْهُ  

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."  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ يُحِبُّ الْعُطَاسَ وَيَكْرَهُ التَّثَاؤُبَ فَإِذَا عَطَسَ أَحَدُكُمْ فَقَالَ الْحَمْدُ لِلَّهِ فَحَقٌّ عَلَى كُلِّ مَنْ سَمِعَهُ أَنْ يَقُولَ يَرْحَمُكَ اللَّهُ وَأَمَّا التَّثَاؤُبُ فَإِذَا تَثَاءَبَ أَحَدُكُمْ فَلْيَرُدَّهُ مَا اسْتَطَاعَ وَلاَ يَقُولَنَّ هَاهْ هَاهْ فَإِنَّمَا ذَلِكَ مِنَ الشَّيْطَانِ يَضْحَكُ مِنْهُ