"A Muslim has four duties towards another Muslim: to say 'may Allāh have mercy on you' when he sneezes, to respond when he invites him, to attend his funeral when he dies, and to visit him when he is sick." This was narrated by al-Bukhārī in "al-Adab al-Mufrad" (923), Ibn Mājah (1/438), Ibn Ḥibbān (2064), and Baḥshal in "Tārīkh Wāsiṭ" (p. 217), al-Ḥākim (1/349 and 4/264), and Aḥmad (5/273) from ʿAbd al-Ḥamīd ibn Jaʿfar from his father from Ḥakīm ibn Aflaḥ from Abū Masʿūd from the Prophet (ṣallá Allāhu ʿalayhi wa-sallam) who said it. Al-Ḥākim said: "Authentic according to the criteria of the two Shaykhs!" and al-Dhahabī agreed with him! This is what they said, but it is one of their errors for several reasons: First, this Ḥakīm was not included by the two Shaykhs in their "Ṣaḥīḥayn," but al-Bukhārī included him in "al-Adab al-Mufrad" as you have seen. Second, he is among the unknown narrators; al-Dhahabī said in his biography in "al-Mīzān": "His only narrator is the father of ʿAbd al-Ḥamīd ibn Jaʿfar." I say: Therefore, the ḥāfiẓ did not authenticate him but only said: "Acceptable." Third, ʿAbd al-Ḥamīd ibn Jaʿfar was only narrated by al-Bukhārī in a suspended form. And his father, Jaʿfar - who is the son of ʿAbd Allāh ibn al-Ḥakam al-Anṣārī - was only narrated by al-Bukhārī in "al-Adab al-Mufrad" as well. I say: From this, you learn the error of the commentator on "Tahdhīb al-Kamāl" in his statement (7/162): "And its isnād is authentic." Yes, the ḥadīth is authentic from the narration of Abū Hurayrah with the wording: "The rights of a Muslim over another Muslim are five... and in another narration: six." He mentioned these four and added: