A.T. Robertson Commentary Ephesians 4:29

"Let no corrupt speech proceed out of your mouth, but such as is good for edifying as the need may be, that it may give grace to them that hear." — Ephesians 4:29 (ASV)

Corrupt (σαπρος). Rotten, putrid, like fruit (Matthew 7:17f.), fish (Matthew 13:48), here the opposite of αγαθος (good).

For edifying as the need may be (προς οικοδομην της χρειας). "For the build-up of the need," "for supplying help when there is need." Let no other words come out.

That it may give (ινα δω). For this elliptical use of ινα see on 5:33.