Is it permissible for a Muslim to combine the 'Isha prayer with the Maghrib prayer due to work necessity?

You must perform the five daily prayers at their known legal times as long as night and day are distinguishable, for Allah, the Almighty, says: "Indeed, prayer has been decreed upon the believers a timed ordinance." (Quran 4:103). It is not permissible to pray the obligatory prayer before its time, as the entry of its time is a condition for the validity of the prayer. It is permissible to combine two prayers (such as Dhuhr and Asr, or Maghrib and Isha) either by advancing or delaying them, when there is an excuse and hardship, provided that it is not a permanent habit. The evidence for this is the Hadith (definition) of Ibn Abbas that the Prophet, peace and blessings be upon him, combined prayers in Medina without fear or rain, so as not to cause hardship to his Ummah.