Musar for Sanhedrin 210:5

It may well be that this is what Rashi meant when he described the שכינה as supplying extra attributes to each of these blessings. When Rashi comments in Sanhedrin 106, that a בת קול, a "heavenly echo," added the words נטע השם in 24,6, this need not be meant literally, but refers to a prophetic insight granted Bileam by G–d at the time, which he was forced to express. Since it had been his original intention to employ the formula of blessing as a curse, the term בת קול used by Rashi is quite appropriate. Just as an echo is a follow-up to the original sound, so these words were "follow-ups" to the first part of the blessing. In the discussion of the Talmud of Bileam's blessings on folio 105, Rabbi Eleazar says that the words וישם השם דבר בפי בלעם, refers to an angel who instructed Bileam, whereas Rabbi Yonathan says that G–d put a fishhook in Bileam's mouth, i.e. He had to pronounce this prophecy whether he liked it or not.

Another difficulty is the whole question of Bileam cursing the people. What possible difference could it make to G–d if Bileam did or did not curse Israel, seeing that G–d Himself had blessed the nation with peace? – Let us look at the way the Talmud in Berachot 7a, and in Sanhedrin 105b, treats the statement by the prophet Michah 6,5: "My people, remember what Balak king of Moab plotted against you; and how Bileam son of Be'or responded to him. Recall your passage from Shittim to Gilgal, and you will become aware of the gracious acts of the Lord." In response to the question of what is meant by the "gracious acts of the Lord," Rabbi Eliezer said that Israel should recognize how kindly G–d had dealt with them by not being angry at Israel during the period Bileam had been called to curse them. Had G–d at that time allowed Himself to be angry at Israel, not a shred of it would have been left. This is why Bileam begins by saying: "How can I curse where G–d has not seen fit to curse, how can I damn whom G–d has not damned" (23,8)! According to Berachot 7a Bileam knew the exact moment when G–d was angry. He had wanted to capitalize on the precise moment of the presence of the attribute of Justice within the greater presence of the attribute of Mercy. During that period however, G–d did not allow the attribute of Justice to accompany any part of the attribute of Mercy. Hence Bileam felt stymied This is his lament, "how can I curse when G–d failed to allow for such a possibility?" According to Tosaphot on that folio, Bileam would have been able to condense all his curses by uttering the word כלם "destroy them," into the "רגע," moment, that G–d's anger would have lasted. If however, we say that G–d converted the curses into blessings, the situation becomes quite different. He re-arranged the letters in that word to read “מלך,” and that would have been the reversal of what Tosaphot suggested he could have done. This is the deeper meaning of 23,21: ותרועת מלך בו, "and their king's acclaim is in its midst." As a result, there is no need to say that G–d reversed His usual method of allowing a minor presence of the opposite attribute when another attribute was in the ascendancy. The reason that we do not accept the premise of Ibn Ezra that once G–d's זעם, anger, is active there is no trace of mercy, is that the Torah itself describes G–d as practicing justice and mercy at one and the same time in Exodus 15,6: "Your right hand O Lord, glorious in power, Your right hand O G–d, shatters the foe." While G–d metes out justice to Israel's enemies, He practices mercy with His people. Rashi says specifically that the same right hand, i.e. the same attribute which saves Israel, annihilates its enemies.