The multitude were astonished at his doctrine - God uses the infidelity of some for the edification of others. Had no false doctrine been broached in the world, we had not seen the full evidence of the true teaching. The opposition of deists and infidels has only served to raise up men in behalf of the truth of God, who not only have refuted them, but shown, at the same time, that the sacred testimonies are infinitely amiable in themselves, and worthy of all acceptation. Truth always gains by being opposed.

And when the multitude heard this,.... This wise and full answer of Christ to the posing question of the Sadducees, with which perhaps they had puzzled many, and never had met with their match before:
they were astonished at his doctrine; concerning the pure, perfect, and angelic state of the righteous in the world to come;, and how strongly and nervously he proved the immortality of the soul, and the resurrection of the dead, which were both denied by the Sadducees; and who were so confounded with his answer, proof, and reasonings, that Luke says, "after that they durst not ask him any question at all": and the Scribes were so pleased therewith, that certain of them applauded him, saying, "master, thou hast well said".

At his doctrine - At the clearness and solidity of his answers.