Is it permissible for a Muslim to disavow a disobedient relative who insists on committing sins, and to deny knowing them if asked about them?

It is not permissible to deny lineage if it involves explicit falsehood or leads to the disavowal of lineage. However, it is permissible through insinuation (ta‘rīḍ) and equivocation (tawriyah).

Insinuation (ta‘rīḍ) is speech that has two meanings, where the listener understands something different from what the speaker intends. Its use has been reported in the Sunnah and from the Salaf, such as in the hadith about the death of Abu Talhah's son, and Umm Sulaym's statement: "He has calmed down, and I hope he has found rest."

It is not permissible for a Muslim to deny the lineage of his brother or lie under the pretext of their committing errors. If one is displeased with the state of his wicked relative and is asked about his relationship with him, he may equivocate with a phrase that conveys something contrary to the reality, without denying lineage or lying.