174 – Muʿāwiyah ibn al-Ḥakam (may Allah be pleased with him) reported that the Messenger of Allah ﷺ said, “In this prayer none of people’s speech is appropriate; it is only glorification (tasbīḥ), magnification (takbīr), and the recitation of the Qur’an.” Narrated by Muslim (1).

Vocabulary
• lā yaṣluḥ: lā here is a negating particle; therefore the present-tense verb that follows remains in the indicative. The lām of yaṣluḥ may be vocalized with ḍammah or fatḥah.
• tasbīḥ: the verbal noun of sabbaḥa. It literally means to declare Allah’s transcendence and sanctity, and more broadly, to remember Him by His names, as in the expression “So-and-so is making tasbīḥ,” meaning he is mentioning Allah.

Points derived from the ḥadith
1 – The occasion for the ḥadith was that a man sneezed during the prayer and Muʿāwiyah ibn al-Ḥakam, while still praying, said “May Allah have mercy on you.” The other Companions in the congregation indicated their disapproval, and after the prayer the Prophet ﷺ taught him, saying, “This prayer admits no part of ordinary human speech; it is only tasbīḥ, takbīr, and the recitation of the Qur’an.”
2 – Deliberately addressing people during the prayer—even in the form of a supplication—invalidates the prayer. Hence our jurists state: the prayer is nullified by the kāf of direct address, except when the address is to Allah Most High or to His Messenger Muhammad ﷺ.
3 – Speaking to people while praying constitutes turning away from intimate discourse with Allah, for al-Bukhārī (417) and Muslim (551) relate from Anas and others that the Prophet ﷺ said, “When any one of you is in prayer, he is confiding with his Lord.”