Rashi on Deuteronomy 29:25/רש"י על דברים כ״ט:כ״ה

1לא ידעום [FOR THEY … SERVED OTHER GODS] WHOM THEY KNEW NOT — i.e. in whom they had never experienced any Divine power.

2ולא חלק להם means, He did not give them (the gods) to be their portion (cf. Rashi on Deuteronomy 4:19). Onkelos, however, renders it by לא אוטיבא להון, i.e. they did not bestow upon them any good. As for the expression לא חלק, Onkelos took it thus, explaining also the singular form of the verb: that god which they have chosen for themselves has never given them any חלק, any inheritance or portion.