Yahweh said to Joshua, This day have I rolled away the reproach of Egypt from off you. Therefore the name of that place was called Gilgal, to this day.
Why did God wait to command the circumcision of the new generation until now rather than on the plains of Moab? Perhaps He did so because He wanted to bring the people into the land before enforcing this aspect of the Law. This is consistent with God’s dealings with humankind. He first gives and then asks (cf. Romans 12:1).