The Permissibility of Greeting a Person in Prayer

A person may be praying the greeting of the mosque or the regular voluntary prayer in the mosque, and his brother who is praying comes to him before he prays and greets him, saying: Peace be upon you.
Is the greeting prescribed? And how does he respond to it while he is praying? This often happens.
Greeting a person in prayer, whether it is the regular voluntary prayer, the greeting of the mosque, or the obligatory prayer, the person in prayer indicates his response to the greeting with his hand, raising it like this to indicate that he is aware of it and has responded to it. If the one who greeted him remains until the person in prayer completes his prayer, he responds to him with words. If he leaves, the gesture is sufficient. But is it recommended for a person to greet a person in prayer or not?We say: It is permissible, and if he fears that the person in prayer is distracted, then when he greets him he says: And upon you be peace; because the person in prayer is sometimes distracted,If he greets him, he says: And upon you be peace.
so he does not greet him.