Why do worshippers change their places after performing the obligatory prayer to perform the supererogatory prayer, and is it necessary to do so, and what is the wisdom behind it, and is this action required at home by changing the position of the prayer rug?

The worshipper following the Imam (Ma'mum) is not required to change his spot to perform the supererogatory (Nafl) prayer, unlike the Imam, for whom it is recommended to move from the place where he led the obligatory prayer. This is based on the Prophet's (peace be upon him) saying: "Let not the Imam perform voluntary prayers in the place where he led the obligatory prayer." The wisdom behind this is that every spot where a servant prostrates will bear witness for him on the Day of Resurrection.