Origen, on Exod 11:3

“And the Lord will give favour to his people in the sight of the Egyptians. And Moses was a very great man in the land of Egypt, in the sight of Pharao’s servants, and of all the people.”

“When Moses had come to the place which God shows him, he is not permitted to ascend, but first God says to him, "Loose the tie of the shoes from your feet." None of these things are said to Abraham and Isaac, but they ascend and do not put aside their shoes. The reason for this is perhaps that although Moses was "great," he was nevertheless coming from Egypt, and some fetters of mortality were bound to his feet. Abraham and Isaac, however, have none of these, but "they come to the place."”

Imported from an open dataset — not yet checked against the printed edition.