Are the Friday sermon and prayer valid if the preacher does not pronounce the Shahada (testimony of faith) for Prophet Muhammad, peace and blessings be upon him, and what is the ruling on previous prayers that were conducted in this manner, and is it sufficient to say, "I bear witness that there is no god but Allah, alone without partner, to Him belongs all sovereignty and all praise, and I bear witness that our master Muhammad is His servant and messenger, peace and blessings be upon him"?

Bearing witness to the Message (of Prophet Muhammad) is not among the pillars of the Friday sermon according to the four madhhabs. The pillars of the sermon, according to the Shafi'is, are five: praising Allah Almighty, sending blessings upon the Prophet, peace be upon him, enjoining piety towards Allah Almighty, reciting something from the Qur'an, and supplicating for the believing men and women. Shaykh al-Islam Ibn Taymiyyah held the view that mentioning the testimony to the Prophet's Message, peace be upon him, is obligatory in the Friday sermon because it is the beginning of entry into Islam, and because "every sermon that does not contain the testimony is like a severed hand." The majority of scholars have held that mentioning the testimony to the Message is not a condition for the validity of the Friday sermon. Therefore, whoever omits it, their sermon and prayer are valid, although it is better to include it due to its establishment in the Sunnah and to avoid scholarly disagreement.