وَعَنْ عَلِيٍّ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: لِلْمُسْلِمِ عَلَى الْمُسْلِمِ سِتٌّ بِالْمَعْرُوفِ: يُسَلِّمُ عَلَيْهِ إِذَا لَقِيَهُ وَيُجِيبُهُ إِذَا دَعَاهُ وَيُشَمِّتُهُ إِذَا عَطَسَ وَيَعُودُهُ إِذَا مَرِضَ وَيَتْبَعُ جِنَازَتَهُ إِذَا مَاتَ وَيُحِبُّ لَهُ مَا يُحِبُّ لِنَفْسِهِ رَوَاهُ التِّرْمِذِيّ والدارمي
Ali (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him and his family) said: "A Muslim has six rights over another Muslim according to custom: When he meets him, he should greet him with salam; when he invites him, he should accept it; when he sneezes (and says 'Alhamdulillah'), he should say to him 'Yarhamuk Allah'; when he falls ill, he should visit him; when he dies, he should attend his funeral; and he should like for him what he likes for himself." Its chain is weak. Narrated by al-Tirmidhi and al-Darimi.