Albert Barnes Commentary Judges 13:18

"And the angel of Jehovah said unto him, Wherefore askest thou after my name, seeing it is wonderful?" — Judges 13:18 (ASV)

Secret - Rather, wonderful, as in the margin. In Judges 13:19 the Angel did wondrously, probably as the Angel that Appeared to Gideon had done, bringing fire from the rock. See the marginal references and notes.