Sforno on Deuteronomy 29:25/ספורנו על דברים כ״ט:כ״ה

1אלוהים אשר לא ידעום, they did not even know of such a deity’s existence. For such unproven and almost anonymous deities they abandoned their G’d, the One Who had been proven as true, powerful, through all the miracles He had performed for them.

2ולא חלק להם, a deity, be it a horoscope or whatever which He had not assigned to them. The reason G’d had never assigned such a horoscope to them had been to show them that they did not need it, as did the other nations. Moses had mentioned in Deut. 4,19-20 that G’d had assigned such intermediaries to the gentile nations.