Exegesis:

kai palin eipen ‘and again he said,’ indicating not only repetition (v. 20), but also continuation, here the addition of a similar parable (v. 21).

Translation:

Again he said, or, ‘furthermore he said,’ “he went on” (An American Translation). For the rest of the verse see again 7.31, first question.

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.