Malbim (14-15): Yonadav's words were fulfilled, even though (a) he is a person, (b) his descendants never transgressed, (c) his descendants did not know any benefit from his words, just they heeded their father's command. Why did you not heed Me? (a) I am Elokim, (b) I spoke constantly (warned you via Nevi'im), and (c) there is benefit from My words (you will dwell on the land)!