Rashi on Exodus 5:19/רש"י על שמות ה׳:י״ט

1ויראו שטרי בני ישראל The meaning is: AND THE BAILIFFS OF THE CHILDREN OF ISRAEL DID SEE [THEM] i. e. their fellow-lsraelites who were ruled by them,

2ברע — they saw them in the misfortune and trouble that befell them, because they had to make the labour hard upon them. לאמר לא תגרעו וגו׳ BY SAYING, YE SHALL NOT DIMINISH etc.