What is the ruling on the prayer of students residing for study in a city 90 km away from their original village, and do they shorten the prayer or complete it, especially since they act upon a fatwa that necessitates shortening, based on the fatwas of Sheikh Al-Islam Ibn Taymiyyah?

Scholars have differed on the duration of stay after which a traveler must pray his full prayers. Malik, Shafi'i, and Ahmad held that he prays in full if he intends to stay for more than four days, while Abu Hanifa held that he shortens his prayers unless he intends to stay for more than fifteen days. As for Sheikh al-Islam Ibn Taymiyyah, he was of the opinion that a traveler shortens his prayers unless he intends an indefinite stay, citing the actions of the Prophet (peace be upon him) and his Companions as evidence. The most sound and cautious view for a Muslim is that of Malik and Shafi'i, while keeping in mind that there is no definitive text on this issue.