Is it permissible for a traveler staying three days to pray Maghrib and Isha without shortening the prayers, and is it permissible to follow him in prayer, and is it permissible for someone who intended to shorten the prayers to pray Maghrib then complete the Isha prayer as a follower?

A traveler is permitted to shorten prayers if the distance traveled is approximately 83 kilometers. This shortening of prayers continues if the traveler intends to stay for less than four days, or if he has no specific intention due to indecision. However, the traveler must pray the full prayers if he intends to stay for four days or more, according to the Maliki, Shafi'i, and Hanbali schools, though they differed on counting the days of arrival and departure. As for the Hanafis, a traveler prays the full prayers if he intends to stay for fifteen days or more.

Regarding the issue of praying Maghrib behind an Imam who is praying Isha, there is a difference of opinion among jurists. The majority view is that it is impermissible, as the prayer becomes invalid due to the difference in intention between the follower (Ma'mum) and the Imam. However, Al-Shafi'i and Ahmad, in one of his two opinions, permitted it.

Furthermore, catching one rak'ah of Isha prayer behind an Imam who is praying in full, and then shortening the rest of the prayer, is not permissible according to the relied-upon opinions of the four schools of thought.