Rashi on Exodus 5:6/רש"י על שמות ה׳:ו׳

1הנגשים THE TASKMASTERS — These were Egyptians, and the שוטרים, bailiffs, were Israelites (cf. vv. 14, 15, 19) (Exodus Rabbah 5:18). A taskmaster (נוגש), was given charge over many bailiffs, and a שוטר was one who was appointed to have control over the workmen.