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.