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  

The Prophet ﷺ said, " If anyone of you sneezes, he should say 'Al-Hamduli l-lah' (Praise be to Allah), and his (Muslim) brother or companion should say to him, 'Yar-hamuka-l-lah' (May Allah bestow his Mercy on you). When the latter says 'Yar-hamuka-llah", the former should say, 'Yahdikumul-lah wa Yuslih balakum' (May Allah give you guidance and improve your condition).  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا عَطَسَ أَحَدُكُمْ فَلْيَقُلِ الْحَمْدُ لِلَّهِ وَلْيَقُلْ لَهُ أَخُوهُ أَوْ صَاحِبُهُ يَرْحَمُكَ اللَّهُ فَإِذَا قَالَ لَهُ يَرْحَمُكَ اللَّهُ فَلْيَقُلْ يَهْدِيكُمُ اللَّهُ وَيُصْلِحُ بَالَكُمْ  

Two men sneezed before the Prophet. The Prophet ﷺ said to one of them, "May Allah bestow His Mercy on you," but he did not say that to the other. On being asked (why), the Prophet ﷺ said, "That one praised Allah (at the time of sneezing), while the other did not praise Allah."  

عَطَسَ رَجُلاَنِ عِنْدَ النَّبِيِّ ﷺ فَشَمَّتَ أَحَدَهُمَا وَلَمْ يُشَمِّتِ الآخَرَ فَقِيلَ لَهُ فَقَالَ هَذَا حَمِدَ اللَّهَ وَهَذَا لَمْ يَحْمَدِ اللَّهَ  

Two men sneezed before the Prophet ﷺ and he said Tashmit to one of them, while he did not say Tashmit to the other. So that man said, "O Messenger of Allah ﷺ! You said Tashmit to that fellow but you did not say Tashmit to me. "The Prophet ﷺ said, "That man praised Allah, but you did not praise Allah."  

سَمِعْتُ أَنَسًا ؓ يَقُولُ عَطَسَ رَجُلاَنِ عِنْدَ النَّبِيِّ ﷺ فَشَمَّتَ أَحَدَهُمَا وَلَمْ يُشَمِّتِ الآخَرَ فَقَالَ الرَّجُلُ يَا رَسُولَ اللَّهِ شَمَّتَّ هَذَا وَلَمْ تُشَمِّتْنِي قَالَ إِنَّ هَذَا حَمِدَ اللَّهَ وَلَمْ تَحْمَدِ اللَّهَ  

When the Messenger of Allah ﷺ sneezed, he placed his hand or a garment on his mouth, and lessened the noise. The transmitter Yahya is doubtful about the exact words khafada or ghadda (lessened).  

كَانَ رَسُولُ اللَّهِ ﷺ إِذَا عَطَسَ وَضَعَ يَدَهُ أَوْ ثَوْبَهُ عَلَى فِيهِ وَخَفَضَ أَوْ غَضَّ بِهَا صَوْتَهُ شَكَّ يَحْيَى  

The Jews used to try to sneezes in the presence of the Prophet ﷺ hoping that he would say to them: "Allah have mercy on you!" but he would say: May Allah guide you and grant you well-being!  

كَانَتِ الْيَهُودُ تَعَاطَسُ عِنْدَ النَّبِيِّ ﷺ رَجَاءَ أَنْ يَقُولَ لَهَا يَرْحَمُكُمُ اللَّهُ فَكَانَ يَقُولُ يَهْدِيكُمُ اللَّهُ وَيُصْلِحُ بَالَكُمْ  

When one of you yawns, he should keep his mouth shut with the help of his hand, for it is the devil that enters therein.  

سَمِعْتُ ابْنًا لأَبِي سَعِيدٍ الْخُدْرِيِّ يُحَدِّثُ أَبِي عَنْ أَبِيهِ قَالَ قَالَ رَسُولُ اللَّهِ ﷺ إِذَا تَثَاوَبَ أَحَدُكُمْ فَلْيُمْسِكْ بِيَدِهِ عَلَى فِيهِ فَإِنَّ الشَّيْطَانَ يَدْخُلُ  

When one of you yawns, he should try to restrain it with cue help of his hand since it is the Satan that enters therein.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا تَثَاوَبَ أَحَدُكُمْ فَلْيُمْسِكْ بِيَدِهِ فَإِنَّ الشَّيْطَانَ يَدْخُلُ