What is the ruling on delaying the Dhuhr prayer until the time of Asr after departing and Dhuhr time has begun?

If a Muslim is traveling and has stopped, then departs after the time for Dhuhr prayer has begun, and he delays the Dhuhr prayer and combines it with Asr prayer during its time, this is permissible, even if it is not the most preferable. It is preferable for a traveler who is on the move to delay Dhuhr until the time for Asr and combine them. However, if one is not traveling and deliberately delays Dhuhr until the time for Asr, he is sinful if the delay was not due to an excuse.