<p>4:29- see on Mt. 12:33.</p><p><i>Let no corrupt speech proceed out of your mouth, but as the need arises, speak that which is good for encouragement, that it expresses grace to those that hear you</i>- As observed on :28, Paul's converts included some rough types- liars, those who stole so much they didn't have a day job, and those who used &quot;corrupt speech&quot;. Paul's hope for their transformation was realistic because he believed in the huge available power of the internal gift of the Spirit. He hoped that those who once stole would work and <i>give</i> to the needy; and here he sees the possibility for those with foul mouths to instead come to use language that was expressing grace, reflecting the <i>charis</i> or gift of the Spirit within them, in a way which would transfer that grace to them too. Such corrupt fruit of the lips cannot grow on a good tree (Lk. 6:43 s.w.). There would either be transformation, or the corrupt tree would be cut down. But that was for the Lord to do; Paul's view of the body of Christ was that it would include such immature people. &quot;Encouragement&quot; is the same word used in :16 for 'building up'. Coarse language and terminology is not going to build up the rest of the body; our words and conversation should be a reflection of our sense that we have a role to play in building up our hearers. The hearers in view are therefore other members of the Lord's body.</p>