But he answered and said unto them, When it is evening, ye say, It will be fair weather: for the heaven is red.
Christ reminds them that His power was manifest enough to reveal the time of visitation, had they not willfully shut their eyes against the clearest light. He asks why they cannot recognize the kingdom of God when it is marked by signs no less evident than those by which you read the sky, proving they are blinded not by error but by deliberate malice, caring only for earthly things and nothing for what is spiritual.
AI summary
You judge the weather by signs in the sky; the redness you observe tells you fairly well what tomorrow will bring. My miracles and the state of Judea are signs no less clear by which you ought to judge these times. Yet you see them and remain blind to what they mean.
AI summary
When the sun sets and the sky turns red, you say fair weather follows, reading the thin clouds in that color. Christ offers no other answer: He has wrought sufficient miracles to prove His Messiahship, yet they demand still more, refusing to read the signs already given.
AI summary