A.T. Robertson Commentary Acts 2:47

"praising God, and having favor with all the people. And the Lord added to them day by day those that were saved." — Acts 2:47 (ASV)

Having favor (εχοντες χαριν). Cf. Luke 2:52 of the Boy Jesus.

Added (προσετιθε). Imperfect active, kept on adding. If the Lord only always "added" those who join our churches. Note verse 41 where same verb is used of the 3,000.

To them (επ το αυτο). Literally, "together." Why not leave it so? "To the church" (τη εκκλησια) is not genuine. Codex Bezae has "in the church."

Those that were being saved (τους σωζομενους). Present passive participle. Probably for repetition like the imperfect προσετιθε. Better translate it "those saved from time to time." It was a continuous revival, day by day. Σωζω like σωτηρια is used for "save" in three senses (beginning, process, conclusion), but here repetition is clearly the point of the present tense.