“The Muslim has four things due from the Muslim: He should answer [by saying Yarhamuk-Allah (may Allah have mercy on you)] to him if he sneezes (and says Al-Hamdulillah); he should accept his invitation if he invites him; he should attend his funeral if he dies; and he should visit him if he falls sick.”
عَنِ النَّبِيِّ ﷺ قَالَ لِلْمُسْلِمِ عَلَى الْمُسْلِمِ أَرْبَعُ خِلاَلٍ يُشَمِّتُهُ إِذَا عَطَسَ وَيُجِيبُهُ إِذَا دَعَاهُ وَيَشْهَدُهُ إِذَا مَاتَ وَيَعُودُهُ إِذَا مَرِضَ