What is the ruling on the second congregation in the mosque while the first is present?

The questioner : May Allah reward you, O Shaykh. A group of people entered the mosque and found that they had missed the congregation, and the imam was saying the closing salam. They prayed a second congregation. During that, the imam of the first congregation remembered that he had not completed a rak'ah, as he had prayed the midday prayer with only three rak'ahs. He stood up to complete it. The imam of the second congregation hesitated: should he break his prayer and join the first congregation, or continue his prayer? The imam bowed, prostrated, and said the salam, but this man was still hesitating whether to break his prayer or not. Then he broke his prayer due to his hesitation regarding his intention, and he and his congregation prayed again. My question is: is he required to break his prayer and join the first congregation?

The Shaykh : Yes, I see that he should break his prayer and join the first congregation. This is a rare issue, very rare in occurrence. I mean, it needs to be written in new scholarly works on Islamic jurisprudence, because it has not come to my attention in the words of previous jurists. However, we have not grasped everything, but it is a rare issue. So we say that it is better for these people to break their prayer and join the imam, because by doing so they gain the multitude of the gathering and they gain the primary congregation, which has the virtue of twenty-seven degrees. Their second congregation does not have twenty-seven degrees, but it is better than praying alone, as the Prophet (peace and blessings be upon him and his family) said: So they do not attain the twenty-seven degrees, but they are better off than if they had not prayed alone. So I say that the best in this situation is for them to break their prayer and join the imam to catch the rak'ah. When he says the salam, they complete what remains. Did you understand? As for this man who hesitated, his prayer is not invalidated by the hesitation, because he did not hesitate about entering [the first congregation]; rather, he hesitated about breaking [his current prayer]. Hesitation about breaking does not harm until he actually breaks it. As for hesitation about entering, yes, it prevents entering. So pay attention to this rule: "Hesitation about entering prevents entering, and hesitation about breaking does not break" Why? Because the original state in the first case is the original state of not entering; as long as you are hesitating, you do not enter. And in the second case, the original state is not breaking; so continue until you break it. For this reason, if a fasting person intends to eat or drink but does not eat and does not drink, is his fasting invalidated or not? It is not invalidated. A praying person intends to break his prayer because he forgot something, but he did not break it; his prayer is not invalidated until he actually breaks it, until he resolves to exit it. So pay attention to this benefit: "Hesitation about breaking is not like breaking, and hesitation about entering is not entering" Yes.