Is it permissible for a traveler to combine and shorten the 'Isha prayer after the Maghrib prayer if he prays behind a resident Imam, and is this permissibility affected by the condition of having a unified intention or the intention of combining before the first prayer?

A traveler is permitted to combine two prayers even if their Imam does not combine them. They are also allowed to pray each prayer behind a different Imam, or to lead one and be a follower in the other. It is not a condition for the Imam to intend combining the prayers; rather, the traveler themselves must intend to combine before commencing the first prayer. The important factor is the traveler's intention to combine, and the unity of intention between the Imam and the follower is only required for a single prayer, not for two combined prayers.

Al-Buhuti said: "It is not a condition for combining prayers to have the same Imam or follower. So, if one prays the first prayer alone, then the second as an Imam or follower, or if one leads the first prayer and another leads the second, or if one prays the first prayer as a follower behind an Imam and another person prays the second, or if one intends to combine behind someone who does not combine, or if an Imam intends to combine for those who do not combine, it is valid."