Rashi: As if to say that from the gods who are near, ¹ of whose worthlessness you are aware, you can be sure that those that are distant - are equally worthless. ²

Seforno: To teach us that, despite the fact that those that are near you won't worship anyway - since you know them to be false; and those that are far you won't worship either, since they are too far to reach (Nevertheless, the Meisis is sentenced to death for enticing - PF).

Rashi: It is a reference to the sun, the moon and the hosts of the heaven that traverse the sky from one end of the world to the other. ¹

Seforno: It is an elaboration of "ha'Rechokim mimcha".