## In the meantime ##

"While they were doing that"

## many thousands of the multitude ##

"thousands of people" or "a very great crowd"

## they trampled each other ##

This is an exaggeration in order to express how many people there were. It means "they were stepping on each other." (See: [[rc://en/ta/man/translate/figs-hyperbole]])

## he began to say to his disciples, first of all ##

"Jesus first started speaking to his disciples, and said to them"

## Beware ##

"Be alert to the danger of" or "Guard yourself against"

## the yeast of the Pharisees, which is hypocrisy. ##

This is a metaphor. It can be translated as a simile "the hypocrisy of the Pharisees, which is like yeast." Just as yeast spreads through a whole lump of bread dough, their hypocrisy was spreading through the whole community. This whole warning can be translated as "Be careful that you do not become hypocrites like the Pharisees. Their evil behavior influences everyone just as yeast affects a lump of dough." (See: [[rc://en/ta/man/translate/figs-metaphor]])