Does the spirit of the Prophet, peace and blessings be upon him, attend the completion of the Holy Quran, and what is the correct [ruling/information] regarding the time of completion?

What is circulated about angels descending when the Quran is completed is incorrect. Rather, it is one of the delusions of some Sufis and the ignorance of some preachers. It has been reported from the Salaf that the person who completes the Quran has a prayer that is answered, and that mercy descends upon completion. Some of the Salaf would gather their family and children upon completion and supplicate.