17 οὕτως πᾶν δένδρον ἀγαθὸν καρποὺς καλοὺς ποιεῖ, τὸ δὲ σαπρὸν δένδρον καρποὺς πονηροὺς ποιεῖ. 18 οὐ δύναται δένδρον ἀγαθὸν καρποὺς πονηροὺς ποιεῖν οὐδὲ δένδρον σαπρὸν καρποὺς καλοὺς ποιεῖν. 19 πᾶν δένδρον μὴ ποιοῦν καρπὸν καλὸν ἐκκόπτεται καὶ εἰς πῦρ βάλλεται.
In the ESV, these verses are:
17 'So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. 18 A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. 19 Every tree that does not bear good fruit is cut down and thrown into the fire.'
In each of these verses, the phrase "good fruit" alliterates and has a balanced number of syllables, even though it's plural in verses 17 and 18 (καρποὺς καλοὺς) but singular in verse 19 (καρπὸν καλὸν). These features provide a euphony that matches the description "good."
