عَنْ أَبِي مَسْعُودٍ رَضِيَ اللَّهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ ((لِلْمُسْلِمِ عَلَى الْمُسْلِمِ أَرْبَعُ خِلَالٍ أَنْ يُجِيبَهُ إِذَا دَعَاهُ وَيُشَمِّتَهُ إِذَا عَطَسَ وَإِذَا مَرِضَ أَنْ يَعُودَهُ وَإِذَا مَاتَ أَنْ يَشْهَدَهُ))
Sayyiduna Abu Mas’ud (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: A Muslim has four rights over another Muslim: when he invites him, he should accept his invitation; when he sneezes, he should say to him “Yarhamukallah” (may Allah have mercy on you); when he falls ill, he should visit him; and when he passes away, he should attend his funeral prayer.