Commentaire sur Le Deutéronome 29:25

לא ידעום [FOR THEY … SERVED OTHER GODS] WHOM THEY KNEW NOT — i.e. in whom they had never experienced any Divine power.

GODS THAT THEY KNEW NOT — “gods in whom they had never experienced any Divine power. ‘V’LO CHALAK LAHEM’ (AND THAT HE HATH NOT ALLOTTED UNTO THEM) — He did not give these [gods] to them [Israel] to be their portion. And Onkelos rendered this expression: v’lo otiva l’hon, meaning, ‘they had not done them any good.’ [Onkelos thus explained] the term chalak as meaning, ‘that god which they have chosen for themselves has never chalak (apportioned) them any inheritance or portion.” This is Rashi’s language. The correct interpretation is: “gods that they knew not as gods, that is to say, [they worshipped gods] whom they knew not as having acted with any Divine power inherent to their essence. And the Eternal, the G-d of their fathers did not allot them [these gods] to them, meaning that He did not designate them as lords over Israel as He placed them over the nations.” I have already explained this.⁴¹See Leviticus 18:25, and above, 4:19.

אלוהים 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.