Rashi on Deuteronomy 13:8/רש"י על דברים י״ג:ח׳

1הקרבים אליך או הרחקים [LET US GO AND SERVE OTHER GODS … NAMELY, OF THE GODS] WHICH ARE NIGH UNTO THEE, OR FAR OFF [FROM THEE] — To what end does it (Scripture) mention the gods of the near nations and those of the far-off ones? But this is in effect what Scripture says: From your knowledge of the gods of the near nations, you may draw conclusions regarding the nature of the gods of those far-off; just as there is nothing real in those of the near ones so there is nothing real in those of the far-off ones (Sanhedrin 61b; Sifrei Devarim 88:1).

2מקצה הארץ [GODS … FAR OFF FROM THEE] FROM THE ONE END OF THE EARTH [EVEN UNTO THE OTHER END OF THE EARTH] — This refers to the sun, the moon and the host of heaven (the stars) who move from one end of the world to the other (Sifrei Devarim 88:2).