Is it a condition to perform ghusl before uttering the Two Testimonies (Shahadatayn) to embrace Islam, by analogy with the story of Thumamah ibn Uthal?

Ghusl (ritual bath) is not a condition for embracing Islam. However, scholars have differed regarding its obligation for a new convert. Malik, Abu Thawr, and Ibn al-Mundhir held it to be obligatory, while Abu Bakr and Al-Shafi'i deemed it recommended, unless there was a state of major ritual impurity (janabah) during the time of his disbelief. Abu Hanifa did not consider it obligatory at all.

Those who maintain its obligation cite the hadith of Qais bin Asim, in which the Prophet, peace and blessings be upon him, commanded him to perform ghusl upon his conversion. Conversely, those who deny its obligation or consider it recommended argue that there is no general command for everyone who converts to perform ghusl, and because the Prophet, peace and blessings be upon him, did not command Mu'adh to perform it when he called the people of Yemen to Islam. The preponderant view is that this ghusl is recommended, not obligatory.