NET

1 Meanwhile, when many thousands of the crowd had gathered so that they were trampling on one another, Jesus began to speak first to his disciples, “Be on your guard against the yeast of the Pharisees, which is hypocrisy.

Darby

The Yeast (Leaven) of the Pharisees

1 In those [times], the myriads of the crowd being gathered together, so that they trod one on another, he began to say to his disciples first^D7323, Beware^D7324 of the leaven of the Pharisees, which is hypocrisy;

Darby Bible Notes

first - Some read 'first of all beware.' but needlessly, I think. It was the first thing on his heart to tell them. Beware - See Note to Matt. 16.6.

KJV

The Yeast (Leaven) of the Pharisees

1 In the mean time, when there were gathered together an innumerable multitude of people, insomuch that they trode one upon another, he began to say unto his disciples first of all, “Beware ye of the leaven of the Pharisees, which is hypocrisy.”