Likutei Moharan 36:6/ליקוטי מוהר"ן ל״ו:ו׳

16. And this is a major principle: From the mouth of the Most High comes only undifferentiated light. However, depending on the aspect of the vessel that receives the light, that is how the light within it takes shape. If the vessel is whole, then he receives full <light>. But if, God forbid, the vessel is not whole, then he receives <the light> in the aspect of me’orot lacking a vav, as is written, “The me’eirat (curse) of God is on the house of the wicked” (Proverbs 3:33). This is, “the righteous will go in them….”

2For the undifferentiated light that comes from Above is [in] an aspect of closed and sealed, <and only afterwards the light opens>. But with regard to the aspect of the vessels of those who receive it, it is <in> an aspect of TZeYRey. The light niTZtaYeiR (takes shape) commensurate with the aspect of the vessel.

3{“It is a blessing that I have taken, and when there is such blessing, I cannot reverse it” (Numbers 23:20).} Therefore, it is said in connection with Bilaam, “It is BaReiKh that I have taken”—with a KaMaTZ —“and when there is such BeiReiKh, I cannot reverse it”—with a tzeyrey. For even the “taking,” in general an aspect KMiTZ (closed) and sealed, was an aspect of beireikh. <He would have wanted the light to take shape coinciding with his vessel, which is an aspect of curse, of me’orot lacking [a vav]. But he was unable to shape it or respond in accord with his aspect.> This is the meaning of “and when there is such beireikh, I cannot reverse it.”

4And why <was it so>? It was because, as Scripture attests concerning them, <[the Jewish people] had pure and clear vessels>. As Rashi explains regarding “HachanokhY” (Numbers 26:5): My name bears witness for them—<that they are the Tribes of> YaH, <which are> mentalities. As is brought in the Midrash: The nations would say, “If over their bodies they had control, [then certainly over their wives].” Therefore, Scripture bore witness concerning them (Shir HaShirim Rabbah 4:12).

5This is also as is written (Deuteronomy 11:26), “See, this day I set before you [blessing and curse].” The language is exact. Above, [the light] is in an aspect of kamatz, closed and sealed. But “before you,” below, the light takes shape in accordance with the aspect of the vessel.

6It was because of this that Bilaam advised Balak to entice them with immorality, in order to ruin their vessels. This is as the medical experts write, that castration cures insanity <so that the mentalities become pure and clear, as above>. And this <corresponds to> “The ascent of Yesod is until Abba and Imma”—i.e., corresponding to “My name bears witness for them.”