When one of you sneezes, he should say 'Alhamdulillah', his brother or companion — くしゃみ
إِذَا عَطَسَ أَحَدُكُمْ فَلْيَقُلْ الْحَمْدُ لِلَّهِ وَلْيَقُلْ لَهُ أَخُوهُ أَوْ صَاحِبُهُ يَرْحَمُكَ اللَّهُ فَإِذَا قَالَ لَهُ يَرْحَمُكَ اللَّهُ فَلْيَقُلْ يَهْدِيكُمُ اللَّهُ وَيُصْلِحُ بَالَكُمْ
音写: Idhaa 'atasa ahadukum falyaqul alhamdu lillaah, walyaqul lahu akhoouhu aw saahibuhu yarhamukallah, fa-idhaa qaala lahu yarhamukallah falyaqul yahdeekumullaahu wa yuslihu baalakum
翻訳: When one of you sneezes, he should say 'Alhamdulillah', his brother or companion should say 'Yarhamukallah', then he should reply 'Yahdikumullah wa yuslihu baalakum'. (The complete sneezing etiquette)
出典: Bukhari 7:125