Then they understood that he didn’t tell them to beware of the yeast of bread, but of the teaching of the Pharisees and Sadducees.
12. Then they understood. The word leaven is very evidently used by Christ as contrasted with the pure and uncorrupted word of God. In a former passage, (Matthew 13:33,) Christ had used the word in a good sense, when he said that the Gospel resembled leaven; See page 127 of this volume.
Christ speaks of spiritual things in earthly pictures, and His disciples hear only bread and butter. They forgot provisions because their minds were filled with better things, which is no small mercy. But mark this: the leaven of the Pharisees, their corrupt principles spreading like yeast through dough, is far more dangerous than an empty pantry, and disciples stand most in peril from hypocrites who cloak their poison in piety.
AI summary
Commenting on Matthew 16:5-12
Verse 12. Then understood they, etc. After this explanation, they immediately saw that he referred to their doctrines. Erroneous doctrines are like leaven in the following respects: (1.) They are, at first, slight and unimportant in appearance. (2.) They are insinuated into the soul unawares and silently, and are difficult of detection. (3.) They act gradually. (4.) They act most certainly.