It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that a man was attributed with an association from the time of ignorance (Jahiliyyah). Sayyiduna Ubayy (may Allah be pleased with him) told him to bite his father's private part, and he did not speak figuratively. The people looked at him with astonishment because of this insult, but he said: I know what you are feeling within yourselves, while I only have the ability to say this much, because the Messenger of Allah (peace and blessings be upon him) commanded us, saying: When you see someone being attributed to the associations of Jahiliyyah, then say to him without any hint or innuendo: Bite your father's private part.
Hadith Referenceالفتح الربانی / القسم الخامس: مسائل الترهيب من الكبائر وسائر المعاصي / 9737
Hadith Gradingمحدثین:صحیح
Hadith Takhrij«حديث حسن، أخرجه ابن حبان: 3153، والنسائي في الكبري : 8864 ، (انظر مسند أحمد ترقيم الرسالة: 21233 ترقیم بيت الأفكار الدولية: 21553»
Brief Explanation
Benefits: … Shaykh al-Albani rahimahullah said: The Caliph of the Messenger, our master Umar ibn al-Khattab radi Allahu anhu, acted upon this hadith and said: "Whoever boasts about his tribes, then tell him to bite his father's private part." (Ibn Abi Shaybah). (Sahihah: 269)
According to Islamic Shariah, the basis for honoring and respecting any individual is his piety (taqwa). The more pious a person is, the more honored and respected he will be.