Theophylact of Ohrid

"When... the people began to gather in great numbers," the Lord began to rebuke the foolish. Among them were some who desired that Jesus perform a sign from heaven; for they said: the signs He performs are from the earth, and He performs them by the power of Beelzebul, the prince of the world, who has authority over the earth; but He cannot perform signs from heaven, because He is not the Son of the Heavenly Father. …

Commentary on Luke ↗

Augustine of Hippo

Luke indeed relates this in the same place as Matthew, but in a somewhat different order. But who does not see that it is an idle question, in what order our Lord said those things, seeing that we ought to learn by the most precious authority of the Evangelist, that there is no falsehood. But not every man will repeat another's words in the same order in which they proceeded from his mouth, seeing that the order itself makes no difference with respect to the fact, whether it be so or not.

Catena Aurea by Aquinas ↗

Ambrose of Milan

That you may know that the people of the Synagogue are treated with dishonour, while the blessedness of the Church is increased. But as Jonas was a sign to the Ninevites, so also will the Son of man be to the Jews. Hence it is added, They seek a sign; and there shall no sign be given them but the sign of Jonas the prophet. Now as the sign of Jonas is a type of our Lord's passion, so also is it a testimony of the grievous sins which the Jews have committed. …

Catena Aurea by Aquinas ↗

Bede

But as the crowds were gathering, he began to say: This generation is an evil generation: it seeks a sign, and no sign will be given to it except the sign of Jonah. He had been attacked with a double question. Some indeed were slandering him for casting out demons by Beelzebul, to whom this has been answered. …

On the Gospel of Luke ↗