Sayyiduna Sahl bin Sa’d Sa’idi (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said:“If something happens to someone during his prayer, he should say «‏‏‏‏سُبْحَانَ اللَٰه» ‏‏‏‏, and clapping is for women.”This is the narration of Ali bin Khushram. While Abdul Jabbar narrated to us the complete hadith regarding the Prophet (peace and blessings be upon him) going to Banu Amr bin Awf, and at the end of it, he mentioned these words: The Messenger of Allah (peace and blessings be upon him) said:“What is the matter with you that when something happens to you in prayer, you start clapping? Clapping is for women; whoever encounters something in prayer should say «‏‏‏‏سُبْحَانَ اللَٰه» ‏‏‏‏.”Imam Abu Bakr (may Allah have mercy on him) says that tasfiq and tasfih both mean the same (i.e., clapping).

Sayyiduna Abdullah (may Allah be pleased with him) narrates that we used to greet the Prophet (peace be upon him) with salam while he was praying, and he (peace be upon him) would respond to our salam. So when we returned from Najashi (after the migration to Abyssinia), we greeted the Prophet (peace be upon him) with salam (while he was in prayer), but he (peace be upon him) did not respond to our salam. We said, "O Messenger of Allah (peace be upon him), we used to greet you with salam during prayer and you would respond to our salam. (Why did you not respond now?)" The Prophet (peace be upon him) replied: "There is engagement in prayer."

Sayyiduna Zaid bin Arqam (may Allah be pleased with him) narrates that a man would talk to the person standing next to him in prayer until this verse was revealed «‏‏‏‏وَقُومُوا لِلَّهِ قَانِتِينَ» ‏‏‏‏ [ سورة البقرة: 238 ] "And stand before Allah with humility." In the narration of Janab Huthaym, there is this addition: So we were commanded to remain silent and forbidden from speaking.

Hazrat Ismail bin Abi Khalid narrated in the manner of Bundar’s previous hadith, but he stated these words: In the time of the Prophet (peace be upon him), a person would speak to his companion during prayer if necessary, until this verse was revealed «‏‏‏‏وَقُومُوا لِلَّهِ قَانِتِينَ» ‏‏‏‏ [ سورة البقرة: 238 ] "And stand before Allah with devotion." Then we were commanded to remain silent.

Sayyiduna Abdullah (may Allah be pleased with him) narrates that we used to greet the Prophet (peace and blessings of Allah be upon him) with salam during prayer. He narrated similar to the previous hadith, and said that the Prophet (peace be upon him) used to reply to our salam (later the ruling was changed), and he said: "Indeed, there is engagement in prayer." (Therefore, do not reply to salam verbally while in prayer.) I asked Ibrahim, "How do you reply to salam?" He replied, "I reply in my heart."

And the explanation of the evidence that if the person speaking does not know that speaking during prayer is prohibited, then his prayer is not invalidated by his speech.

Sayyiduna Muawiyah bin Hakam Sulami (may Allah be pleased with him) narrates: I said,“O Messenger of Allah, we are newly emerged from ignorance, then Allah brought us the blessing of Islam, and indeed among us are some people who take bad omens.”The Prophet (peace and blessings be upon him) said:“That is something they find in their hearts, so it should never prevent them (from their actions).”I said,“O Messenger of Allah, some people go to soothsayers.”The Prophet (peace and blessings be upon him) said:“Do not go to them.”They said,“O Messenger of Allah, some of us draw lines.”The Prophet (peace and blessings be upon him) said:“Among the noble Prophets, there was a Prophet who used to draw lines, so whoever’s line coincides with his lines, then it is correct (there is no harm in it).”Sayyiduna Muawiyah (may Allah be pleased with him) says: While I was praying with the Messenger of Allah (peace and blessings be upon him), a man among the people sneezed, so I said to him «‏‏‏‏يَرحَمُكَ الله» ‏‏‏‏“May Allah have mercy on you,”so the people started staring at me. So I said,“Woe to my mother, may she weep for me (meaning, may I die), why are you looking at me like this?”He says: Then the people began striking their hands on their thighs, so when I saw that they were making me silent, I became silent. When the Messenger of Allah (peace and blessings be upon him) finished the prayer, he called me. May my parents be sacrificed for him, I have never seen a better teacher than him before or after him. By Allah, he neither hit me, nor rebuked me, nor spoke harshly to me. He (peace and blessings be upon him) said:“Indeed, in this prayer of ours, people’s speech is not appropriate. Rather, it is for glorifying Allah, declaring His greatness, and reciting the Qur’an.”These are the words of the narration of Mayasarah. The words of the narration of Bundar are: During this, I was praying with the Messenger of Allah (peace and blessings be upon him). Similarly, other narrators have also narrated. And Bundar says: Then when I saw that they were making me silent, I became silent. Imam Abu Bakr (may Allah have mercy on him) says: I have narrated the hadith of the rest of the narrators in“At-Tasneef Al-Kabeer”similar to the narration of Bundar, but I have not mentioned their words.

And the explanation of the evidence that the conversation of such a person performing prayer does not invalidate the prayer.

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led us in two units of prayer from the two evening prayers, either Zuhr or Asr—I think it was the Zuhr prayer. Then the Prophet (peace and blessings be upon him) came to the wooden post in the direction of the qiblah in the mosque and leaned his hands on it, placing one hand over the other. The hasty people left the mosque, saying that the prayer had been shortened. Among the people were Sayyiduna Abu Bakr and Umar (may Allah be pleased with them both), but they were afraid to speak to the Prophet (peace and blessings be upon him). A man, who was called Dhu’l-Yadayn (the one with two hands) because his hands were either short or long, said,“O Messenger of Allah, has the prayer been shortened or have you forgotten?”The Prophet (peace and blessings be upon him) said,“Neither has the prayer been shortened nor have I forgotten.”So he said,“Rather, you have forgotten.”The Prophet (peace and blessings be upon him) asked,“Is Dhu’l-Yadayn telling the truth?”They replied,“Yes.”The Prophet (peace and blessings be upon him) then performed the remaining two units, then gave salam, then said takbir and performed a prostration like his usual prostration or even longer, then raised his head from prostration, (then performed a second prostration). Bundar narrated the complete hadith. Imam Abu Bakr (may Allah have mercy on him) said: I have mentioned this complete chapter in“The Book of Forgetfulness in Prayer.”

It is that when the Messenger of Allah (peace be upon him) calls people to matters that give life, it is obligatory for them to respond to his call, even if they are performing prayer.