תּוֹרָה קכד

When one speaks before the Omnipresent and explains one's conversation with arguments and requests — and wishes to prevail over the Holy One, blessed be He — as it were — that He should fulfil one's request — Hashem Yisborach has great delight and joy from this.

Therefore Hashem Yisborach sends him words into his mouth so that he can prevail.

For without this — certainly it would be impossible for flesh and blood to prevail over Hashem Yisborach. But Hashem Yisborach Himself assists him in this as above.