Rashi on Exodus 7:28/רש"י על שמות ז׳:כ״ח

1ועלו AND THEY SHALL GO UP from the river

2בביתך — first into thine house and afterwards, בבית עבדיך — into the house of thy servants; he took the first step in counselling evil against Israel, as it is stated (1:9) “He spake to his people, “[Behold, the children of Israel are more numerous and powerful than we]”, and with him, therefore, did punishment begin (cf. Sotah 11a and Exodus Rabbah 10:3).