Sforno on Exodus 23:25/ספורנו על שמות כ״ג:כ״ה

1ועבדתם את ה' אלוקיכם, the manner in which you will demonstrate that you indeed serve Him is by destroying all the idols as mentioned in the previous verse. As a corollary of having destroyed idolatry and its representatives you will not need to worry about anyone in your midst trying to convert Jews to such alien religions and to thereby estrange them from serving Me.

2וברך את לחמך, so that it will prove nutritious instead of the source of a variety of intestinal ailments.

3והסירותי מחלה מקרבך, diseases caused by polluted air or climactic conditions.