John Gill Commentary 2 Kings 5:19

"And he said unto him, Go in peace. So he departed from him a little way." — 2 Kings 5:19 (ASV)

And he said to him: That is, the prophet said to Naaman.

go in peace: in peace of mind; be assured that God has pardoned this and all other transgressions.

so he departed from him a little way: about a mile, as the Targum, and so other Jewish writers; of this phrase, (See Gill on Genesis 35:16), some say a land's length, that is, about one hundred and twenty feet; rather it was a thousand cubits, or half a mile.