What is the Shar'i ruling on a mutual promise of marriage between a young man and a young woman after three years with no communication, and will Allah facilitate their marriage with supplication and repentance, and can Allah change destiny to unite them? And can the young man balance his studies and work to be able to marry within this period?

It is forbidden to speak with a non-mahram (definition) woman except out of necessity. There is no sin in promising marriage, and it is recommended to fulfill such a promise. One who repents from a sin is like one who has no sin. Supplication (du'a) averts divine decree and is among the greatest means of sustenance. It is advised to balance work and study, or to focus on study to facilitate marriage.