The ruling on one who has prayed the obligatory prayer, then enters a mosque and finds them praying

Question:
It is stated in al-Rawd: If a man enters the mosque, having already prayed, and the congregation is praying, he does not pray unless the iqamah is called, and he is in the mosque, on the condition that it is not a time of prohibition?

Answer:
Under any consideration, the discussion in al-Rawd, their words, is evaluated against the Book and the Sunnah. This is the standard for the words of the scholars: they are evaluated against the Book of Allah and the Sunnah of His Messenger (peace and blessings be upon him). So whatever agrees with them is accepted.
And the Sunnah indicates that if a person comes to the mosque and the people are praying, he prays with them, whether it is a time of prohibition or not. The Prophet (peace and blessings be upon him) said to Abu Dharr: .
And it is established in the authentic hadith that two men came while the Prophet (peace and blessings be upon him) was praying in Mina. When he finished, it was said to him: They did not enter with him. So he called for them, and they were brought to him, their flanks trembling, and he said to them: He did not say: "Before the iqamah is called." This indicates that whoever comes to the mosque and finds them praying, even if he did not attend the iqamah, he prays with them. But if he attends the iqamah, it is more emphatic. And when the imam concludes the prayer, he makes up what he missed. It becomes a voluntary prayer for him, and he has a reward for that for following the Sunnah.