Anas ibn Mālik (may Allah be pleased with him) reported: Whenever we stopped at a place (during a journey) for rest, we would not offer any (voluntary) prayer until we unloaded the luggage from the riding animals.
Anas (may Allah be pleased with him) reported that when the Companions (may Allah be pleased with him) traveled and then stopped for rest or reached their destination, they would not hasten to perform the supererogatory prayer, despite their keenness to pray, until they unloaded the riding animals that carried their luggage. Out of mercy towards animals, they would hurry to remove the luggage off their backs to relieve them of their loads.