Thou art expert for I know thee to be expert, A.V. and T.R. Expert; γνώστην, here only in the New Testament, but found in the LXX. applied to God, ὁ τῶν κρυπτῶν γνώστης: and 1 Samuel 28:3 and 2 Kings 21:6, as the rendering of ינִעְדֹּיִ, a wizard.
It is seldom found in classical Greek. According to the R.T., which is that generally adopted (Meyer, Kuinoel, Wordsworth, Alford, etc.), the accusative γνώστην ὄντα σέ is put, by a not uncommon construction, for the genitive absolute, as in Ephesians 1:18.
The marginal rendering, because thou art especially expert, seems preferable to that in the text. Customs and questions. For the use of ἔθη and ζητήματα applied to Jewish customs and controversies, see Acts 6:14; Acts 16:21; Acts 21:21, etc.
; and Acts 25:19, note.