And upon it (Yesod) is stated: (Ex. 31:17) Between Me and between the Children of Israel, ‘it is a sign’ ∞ot hi for ever... – ‘the letter Hei’ (ot) hei specifically! And because of this, She (Malkhut) is called Hei ה, after His (Yesod) name: (Gen. 1:31)... the sixth (Ha-shishi) day – the HEi (Malkhut) of ‘the sixth’.
(Ps. 93:4) From the voices sounds of many waters – these are the 7 [voices] Names, which divide into 7 rivers, and all of them are divided, within that river that goes out from Eden.
And they are alluded to in: (Ps. 29:1) Give (Havu) to Y”Y... There are seven that go according to seven Names, which are A-V-G-Y-T-Tz etc., and they are 7 sephirot: