or a Christian, then converts to Islam: "O Jew, O Christian." Meaning: calling him by his former name. Allah forbids the believers from doing that and says: "Wretched is the name of disobedience after [one's] faith" (al-Hujurat: 11). Wretched is the name: Judaism and Christianity after Islam.

Muhammad said: "Al-alqab" (nicknames) and "al-inbaz" (insulting with titles) are one and the same. The meaning is: do not call one another by them, and this is the interpretation of al-Hasan.