«فَأَمْهَلْتُهُ رَيْثَمَا خَلَعَ نَعْلَيْهِ وَغَسَلَ رِجْلَيْهِ»
I allowed him time to remove his sandals and wash his feet.
Amhala is to grant time; raythamā means until or for as long as; khalaʿa is to take off; ghasala is to wash. The narrator does not enter immediately.
This deliberate delay shows the follower choosing his moment. A small physical action makes the coming encounter more convincing.