Is it permissible to combine the Maghrib and Isha prayers in the mosque such that Maghrib is prayed first, immediately followed by the Isha prayer?

Combining the Maghrib and Isha prayers—either by advancing or delaying them—is permissible when there is a valid reason, such as rain or similar circumstances. The condition for this is that the prayers must be combined without any separation between them, and this is the view held by the majority of scholars.