For a good tree bringeth not forth corrupt fruit; neither doth a corrupt tree bring forth good fruit. Corrupt fruit - Καρπον σαπρον, literally, rotten fruit: but here it means, such fruit as is unfit for use. See on Matthew 7:17-20 (note).
Related Commentaries of Luke 6:43
Luke 6:43
43 For a good tree bringeth not forth corrupt fruit; neither doth a corrupt tree bring forth good fruit.