This continues an account of the Pharisees saying that it was by the power of Satan that Jesus healed a man.

## upon you ##

upon the Pharisees

## without tying up the strong man first ##

"without taking control of the strong man first"

## who is not with me ##

“who does not support me” or “who does not work with me”

## is against me ##

“works against me” or "destroys my work"

## gather  ##

This is the common term for harvesting crops. (See: [[rc://en/ta/man/translate/figs-metaphor]])