Exegesis:

thete oun en tais kardiais humōn lit. ‘so lay to your hearts.’ For this phrase cf. on 1.66, but here its meaning is ‘to resolve,’ ‘to make up one’s mind,’ ‘to come to a decision’ (cf. Acts 5.4).

mē promeletan apologēthēnai ‘not to prepare beforehand (how) to defend yourselves.’ For apologeomai cf. on 12.11. Here it refers to the wording of their defence.

promeletaō ‘to practise beforehand,’ ‘to prepare beforehand.’

Translation:

To meditate beforehand, or, ‘to think-out before it happens’ (Tae’).

How to answer, cf. on 12.11. Batak Toba uses here, ‘your-justification (lit. being-cleansed).’

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.