Which is better: praying in an old mosque or in a mosque with a larger congregation?

Prayer in a mosque with a larger congregation is better than prayer in a mosque with a smaller congregation, even if the latter is an old mosque. This is based on the Prophet's (peace and blessings be upon him) saying: "And whatever is more in quantity is more beloved to Allah Almighty." However, if two mosques are equal in the size of their congregation, then the old mosque is better due to the abundance of worship that has taken place therein. Prayer in an old mosque may be prioritized if there is a legitimate religious benefit, such as if the worshipper is an Imam or caretaker of the mosque and the congregational prayer cannot be established except by his presence.