Word by Word Analysis

ثُمَّ نُنَجِّى رُسُلَنَا وَٱلَّذِينَ ءَامَنُوا۟ ۚ كَذَٰلِكَ حَقًّا عَلَيْنَا نُنجِ ٱلْمُؤْمِنِينَ 103

Then We will save Our messengers and those who have believed. Thus, it is an obligation upon Us that We save the believers.