The poor son was glad to be treated kindly, but still thought that he was a humble employee. Therefore, the rich man had him clear dirt for twenty years.

Seeing the truth and meditating on it have taken him ten [years] each: so it is said, “twenty years.”

After that the father and son trusted each other. Now the son felt no hesitation in entering the house of his father [Came and went at his ease]

[The Buddha] had him hear about the Greater Vehicle, and so he came and went to this li at his ease without harboring any doubt.

but still lodged in his old place.

He heard the teaching of the Greater Vehicle preached and was led to know that it was what he had already had, and yet he did not comprehend it: he was “lodged in the same place as before.”