“‘Shir Mizmor (A song, a psalm) to the victor’—sing to the One who is defeated and rejoices.” (Pesachim 119a)

When a person speaks before the Holy One and explains his words using argumentation and entreaties, he wants to defeat God, so to speak. The Holy One takes pleasure from this. He therefore sends him words with which to defeat Him, so to speak, so that He might receive the pleasure. For without this, it would surely have been impossible for a man of flesh and blood to defeat the Holy One. But God Himself sends and makes available to him these words and arguments, so that he might defeat Him, as above.