the speech is brief and the interval is short, it is invalidated, because he has done something incompatible with the prayer, just as if he had broken his ablution.
The correct view is that the prayer is not invalidated by this, because he spoke on the assumption that the prayer had been completed; therefore, he is excused. This will be discussed shortly.
His statement, “like speaking in the midst of it,” means: just as the prayer is invalidated if one speaks during the prayer itself. The author, may Allah have mercy on him, analogized what occurs outside the prayer according to the worshipper’s understanding to what occurs during the prayer itself, because the ruling on speaking during the prayer is established in the hadith of the Prophet, may Allah bless him and grant him peace, who said: “No ordinary speech is suitable during this prayer” (1). Thus, if he speaks after the salutation, having forgotten that something was omitted, his prayer is invalidated, just as it would be if he spoke while praying. According to the madhhab (2), the prayer is invalidated in both cases. The preponderant view is that it is not invalidated by speech uttered forgetfully or out of ignorance, as has preceded and will follow.
“But if it is brief and for its benefit, it is not invalidated.” ………
His statement, “But if it is brief and for its benefit, it is not invalidated”: the author, may Allah have mercy on him, divided speech into categories when someone speaks after giving the salutation forgetfully:
The first category is that he speaks about something unrelated to the benefit of the prayer; in this case, it is invalidated in all circumstances.
The second category is that he speaks for the benefit of the prayer, with brief speech, such as the action of