Is it permissible to delay the Isha prayer until Fajr, or combine it with Maghrib, due to the difficulty of performing it on time because of early work?

Prayer is a temporary obligation that cannot be delayed beyond its prescribed time except for a legitimate excuse, such as travel, fear, rain, hardship, or severe illness. The difficulty of waiting for it is not considered an excuse. Allah has magnified the importance of prayer times, and maintaining them means performing them within their designated period. Even a person unable to fulfill some of the conditions or obligations must pray at the appointed time in whatever state they are able, as is also the case in the fear prayer (salat al-khawf) and prayer during battle. Therefore, it is obligatory to maintain the performance of the Isha prayer at its prescribed time, even with some difficulty.