“It is in this sense, above all, that the raising of the hands in Aaron’s blessing (Lev. 9:22) and during the battle against Amaleq (Exod. 17:11) is explained. The raising of the hands in the priestly blessing, at the end of the ‘Amidah prayer, corresponds to the raising of the hands after the sacrifice (section 87): it is a gesture marking the union of the sefiroth, which are specifically mentioned here as being contained in one another.
The victory of Israel over Amaleq when Moses raised his hands is on the same level. Moses directed the “concentration of the heart,” kawwanath ha-leb, to that middah that is named Israel and that contains the Torah of Truth.
“He indicated with the ten fingers of his hands, that [this middah] gave permanence to the ten [logoi], so that if it [this middah] would not assist Israel, the ten logoi would no longer be sanctified every day—and then Israel was victorious.”
The expression kawwanath ha-leb is taken from the Targum and the Midrash and means concentration of the spirit; from the Book Bahir on it was used by the kabbalists in the sense of “mystical meditation” on the sefiroth. It serves as the fundamental concept of their mysticism of prayer. The Midrash already states that Israel’s prayer is not heard now, for it does not know the full, explicit name of God, shem ha-meforash. If, therefore, someone knows this secret, his prayer will be heard. The same idea is very boldly developed in an interpretation of Habakkuk 3:10 in section 95:
“If there are in Israel enlightened men and such as know the secret of the venerable name and raise their hands, they will be heard immediately, for it says [Isa. 58:9]: “Then, when you call, the Lord will answer.” [This is to be understood as follows:] If you invoke [that which is indicated by the word] ‘az, God answers. And what does this ‘az [composed of ‘alef and zayin] signify? This teaches that it is not permitted to invoke the ‘alef alone or to pray to it, but only together with the two letters that are connected with it and that sit highest in the royal dominion. And together with the ‘alef, they are three. Seven of the logoi [still] remain, and that is signified by [the letter] zayin [whose numerical value is seven] and of this it is also said [Exod. 15:1]: “Then sang,” ‘az yashir, [that is, the ‘az praised] “Moses and the Israelites.”
This reinterpretation of the Hebrew word ‘az utilizes an old nonmystical midrash in which this word in Exodus 15:1 is interpreted according to the numerical value of the two consonants, as if Moses had said: “Let us praise the one who thrones above the seven heavens.”
The new idea is: if you invoke (in your kawwanah ) the ten logoi that represent the secret of the true name of God, then God answers! It is understandable that this passage, which speaks so clearly of a prayer addressed to the logoi and sefiroth, would have been considered offensive.
It evidently was one of the many heretical utterances that, according to Meir ben Simon of Narbonne, filled the Bahir. He specifically taxed the kabbalists with praying to the sefiroth as intermediaries instead of to God, thus making themselves guilty of polytheism.”
Gershom Scholem, Origins of the Kabbalah, pp. 194-6.