What is the ruling on establishing a second congregational prayer after the first one in a mosque that has a regular imam, and is it permissible to prevent brothers from doing so?

Establishing a second congregational prayer in a mosque involves impermissible and permissible scenarios. It is prohibited if there is a prior agreement to divide the Muslim community, or if it is a regular custom in the mosque, due to the division and discouragement from the first congregation that this entails. However, if it is incidental, without prior agreement, such as a group entering after the prayer has concluded, there is a difference of opinion regarding it. The correct view is that it is permissible, even recommended, in order to attain the reward of congregational prayer. The proof for this is the hadith (definition): "A man’s prayer with another man is purer than his prayer alone," and the Prophet, peace and blessings be upon him, encouraged someone to give charity to one who missed the prayer by praying with him. Similarly, repeating the congregation is permissible in mosques in markets and on roads that do not have a regular imam. It is recommended to unite the word and abandon disunity, and to follow Abdullah ibn Mas'ud's saying: "Disagreement is evil." It is also permissible for the Imam to omit some sunan (prophetic traditions) for the sake of uniting the congregation, just as the Prophet, peace and blessings be upon him, refrained from building the Kaaba on the foundations of Ibrahim to conciliate the hearts of the Quraysh.