In prayer, nothing of people's ordinary speech is allowed. Only Tasbīh, Takbīr, and recitation of the Qur'an are allowed
Mu‘āwiyah ibn al-Hakam As-Sulami (may Allah be pleased with him) reported: While I was praying with the Messenger of Allah (may Allah's peace and blessings be upon him) a man sneezed, so I said: "May Allah have mercy upon you." People looked at me disapprovingly, so I s…

