Theophylact of Ohrid

When the mouths of the Pharisees and the Herodians had been shut, again the Sadducees put Him to the test. Their heresy was this: they believed neither in a resurrection of the dead, nor in the existence of an immaterial spirit, nor in angels, and in general took a position opposite to that of the Pharisees. Here they contrive an impossible situation. For supposing that two brothers took her and then died, would not the third consider it an omen and refuse the marriage, learning from those who had preceded him? …

Commentary on Matthew ↗

Jerome

On that day the Sadducees approached him, who say that there is no resurrection. There were two sects among the Jews: the Pharisees and the Sadducees. The Pharisees prioritized the righteousness of traditions and observances, which they call 'second law', and this is why they were referred to as 'separated' from the people. …

Commentary on Matthew ↗

Gregory the Dialogist

But there are who observing that the spirit is loosed from the body, that the flesh is turned to corruption, that the corruption is reduced to dust, and that the dust again is resolved into the elements, so as to be unseen by human eyes, despair of the possibility of a resurrection, and while they look upon the dry bones, doubt that they can be clothed with flesh, and be quickened anew to life.

Catena Aurea by Aquinas ↗

Thomas Aquinas

That day. Here the second question is presented, and he does three things. First, the question is presented; secondly, the response; thirdly, the effect. The second is at but Jesus answering, etc.; the third at and the multitudes hearing it were in admiration. Concerning the first, first the disposition and condition of the questioner is presented; secondly, the question. He says, therefore, that day. And why that day? Not without reason, because when they saw the others confounded, they sought him out not without presumption. …

Commentary on Matthew ↗