The limit for beginning the combining and shortening of prayer for the traveler

The listener Abdulaziz al-Luhaydan from Riyadh sent a question, saying: We were on a student trip, and before the plane took off, we prayed the 'Asr prayer shortened. On the return, we prayed the 'Isha' prayer shortened before the time for 'Isha' had entered. What is the ruling on what we did, and is our prayer valid? May Allah reward you with good.
Answer: If the airport is outside the town, outside the built-up area, and you have resolved to travel, then there is nothing wrong with shortening the four-rak'ah prayers at the airport, because you have commenced the journey. The Prophet (peace and blessings be upon him) shortened the prayer at Dhul-Hulaifah and at the outskirts of Madinah after he had left Madinah (peace and blessings be upon him). So if the airport is like the new airport here in Riyadh, which is outside the town, then there is nothing wrong with shortening the prayer there for the arriving traveler and the departing traveler. The arriving traveler, after he has reached the town, may pray 'Isha', Zuhr, and 'Asr shortened at the airport. And the one who has traveled and left the town, and is waiting for takeoff, and prays Zuhr before takeoff, or 'Asr, or 'Isha' before takeoff, shortened as two rak'ahs, there is nothing wrong with that. Or combining Maghrib and 'Isha' is also without blame, because he has commenced the journey by reaching the airport, which is outside the town.
The presenter: May Allah reward you with good.