What is the appropriate response to someone who says, "May Allah reward you with goodness"? And what is better for expatriates: to pray in the university prayer room or in a mosque located a kilometer away, especially since some prefer the mosque over the prayer room, which has led to a decrease in worshippers at the university?

If someone says to him, "May Allah reward you with good (Jazakallahu Khairan)," it is recommended for him to respond to the one who supplicated by saying something similar to what was said, such as: "And may He reward you (Wa Jazaka)." This is similar to how Aisha, may Allah be pleased with her, used to respond to whoever said to her, "May Allah bless you (Barakallahu feekum)," by saying, "And may Allah bless them (Wa feehim Barakallah)."

As for praying in the university prayer room (musalla), it is permissible. However, it is more virtuous to pray in a dedicated mosque (masjid mawqoof) because it carries a greater reward.