Charles Ellicott Commentary Judges 18:4

"And he said unto them, Thus and thus hath Micah dealt with me, and he hath hired me, and I am become his priest." — Judges 18:4 (ASV)

Thus and thus. —Literally, according to this and according to that, as in 2 Samuel 11:25; 1 Kings 14:5.

I am his priest. —See Judges 17:13. Similarly in the dearth of genuine priests Jeroboam was forced to make even Levites out of the lowest of the people (1 Kings 12:31).