Kept back (enosphisato). First aorist middle indicative of nosphizō, old verb from nosphi, afar, apart, and so to set apart, to separate for oneself, but only here, Act 4:3; Tit 2:10 in the N.T.
His wife also being privy to it (suneiduiēs kai tēs gunaikos). Genitive absolute with second perfect participle of sunoida, to know together with one, “his wife also knowing it together with him.”
Brought a certain part (enegkas meros tōi). Aorist active participle of pherō, for a definite act. The praise of Joseph was too much for Ananias, but he was not willing to turn over all. He wanted praise for giving all and yet he took care of himself by keeping some. Thus he started the Ananias Club that gave a new meaning to his lovely name (God is gracious).