Is it permissible to utter obscene language—including incidents of zina (unlawful sexual intercourse) and liwāṭ (sodomy)—when quoting innovators, and to adopt this as a consistent methodology in sermons to refute them and spread tawḥīd (monotheism)? And what is the ruling on adducing as evidence for this the Quran’s mention of indecency, or the Prophet’s (peace be upon him) action in that regard, or what is attributed to Shaykh Muḥammad ibn ‘Abd al-Wahhāb?

Calling to Allah is one of the best acts of obedience, especially calling to Tawhid (definition) (monotheism). It is an admonition to Muslims to explain Tawhid to them and to warn them against shirk (definition) (polytheism) and superstition. Many common people fall into false beliefs due to ignorance, and they are exploited by the leaders of misguidance. Gentleness is the fundamental principle in da'wah (calling to Islam), just as Allah commanded us to dispute with the People of the Book in the best manner. Gentleness adorns everything it is in and detracts from nothing it is removed from. Harshness is an exception that may be needed with stubborn individuals who display enmity. Warning against books that contain false matters attributed to some individuals for whom sainthood and righteousness are claimed is an obligatory matter, but only to the extent that achieves the intended purpose and not for personal gratification. It is permissible to explicitly mention the names of abhorrent matters when there is a need and a benefit.