Luke 7:30

ἠθέτησαν εἰς ἑαυτούς. ‘Nullified (Galatians 2:21; Proverbs 1:24) the purpose of God, to their own ruin,’ or better, ‘with reference to themselves.’ The “purpose of God” (Acts 20:27) had been their salvation (1 Timothy 2:4). They could not nullify this purpose towards others, but they did so as far as it referred to themselves. Had the meaning been they rejected it ‘to the best of their own power’ we should have τὸ εἰς ἑαυτούς.

μὴ βαπτισθέντες. They seem to have gone to the ministry of John partly out of curiosity, partly as spies (Matthew 3:7); and they consistently refused to recognize him as a Prophet, although they were prevented from shewing open hostility by fear of the people (Mark 11:32).