Is it permissible for a university student whose university is 140 km away to shorten and combine prayers if he leaves on Friday evening and returns on Wednesday afternoon, knowing that some lectures extend from 10 AM to 4 PM?

If the university is located at a qasr (shortening) distance (83 km) from your village, and you arrive at the university village on Friday or Saturday night, and stay there until Wednesday evening, then you are considered a resident. Therefore, it is not permissible for you to shorten or combine prayers, because you have intended a stay of four days.

However, if you arrive at the university village on Saturday morning, you are considered a traveler.

The four-day period of residence is calculated without including the days of arrival and departure if the arrival is during the day. The night following the day of arrival and the day following the night of arrival are included in the calculation.

It is not permissible for you to shorten or combine prayers if you arrive at the university village on Friday evening or Saturday night. You should perform the prayer at its designated time, even if it requires interrupting classes.

It is possible to perform a jum‘ ṣūri (figurative combination) between two prayers by delaying the first one until its last time and performing the second one at the beginning of its time.