Is it permissible to combine the Dhuhr and Asr prayers when going out to buy something from a distant place and it is difficult to find a place to pray before the Maghrib call to prayer due to the long distance and the large size of the city?

The original principle is to pray on time, but it is permissible to combine two prayers when circumstances are difficult and there is great hardship, provided that it does not become a habit. This is the view of the Hanbalis. Thus, it is permissible to combine the Asr prayer with the Dhuhr prayer by performing them together earlier (jam' taqdim).