The Zohar teaches the Tower of Babel’s success was due to its builders speaking Hebrew.
From the teachings of Rabbi Shimon bar Yochai
“The entire earth had one language and a common purpose…: ‘Come, let us build ourselves a city, and a tower whose top will reach the sky. This we will make ourselves a name so that we will not become scattered over the entire earth.'” (Gen. 11:1-4)
Rabbi Shimon said: Until that time, the world had a single foundation, principle and root: belief in the Holy One blessed be He. What is written [subsequently]? “When people migrated from Kedem…” – “Kadmono shel Olam” [the Primordial and Principle One] in whom everyone believed.
The builders of the city spoke the Holy Tongue….
The word “kedem” can be understood literally – “the east” or, as in this case, as referring to the Holy One blessed be He who is called “Kadmono shel Olam”. Thus, the meaning of the verse is: “They abandoned belief in G-d, and began to worship idols.” (Zohar I, 74b)
“The entire earth had one language.” The builders of the city spoke the Holy Tongue [Hebrew], which the ministering angels know, and did not speak any other language. For this reason it is written, “Shouldn’t they be prevented from accomplishing all their objectives?” (ibid. 11:6) Had they spoken a different language, which the ministering angles do not know, they could not have accomplished their objectives, because witchcraft has no permanence.
The builders of the city used their knowledge of the Hebrew language in the use or manipulation of Divine Names….
The meaning of this is as follows: The builders of the city used their knowledge of the Hebrew language in the use or manipulation of Divine Names to force the ministering angels to aid them in their task of building the city and the tower. Had they not known the Holy Tongue, they would not have been able to force the angels to do their bidding. Angels can be manipulated only by using Divine Names which derive from the Hebrew language. Instead, they would have used witchcraft. Since witchcraft has no permanence, whatever they would have achieved thereby would have soon disintegrated of its own accord.
“A common purpose” [also translated as, “a few matters”] means that they knew clearly the rank each of the [multiple] supernal levels without erring between them, [as if they were merely] a few matters. For this reason, [because of their vast knowledge of spiritual matters], they took evil counsel from wisdom, as it is written, “Let us build ourselves a city, and a tower whose top will reach the sky.”
The “city and tower” refer to extremely elevated levels of esoteric wisdom which they dragged into impurity, as will be explained shortly.
They wanted to increase the power of unholiness on earth, and serve the side of impurity….
This matter is the secret of chochma, wisdom [or better, “cunning” since this refers to chochma of the side of unholiness]. They wanted to increase the power of unholiness on earth, and serve the side of impurity, for they knew that from that level all negative aspects descend upon the world. In this way they attempted to drive holiness away.
“A city and a tower”: This refers to supernal chochma, for they knew that the Holy Divine Name is not grasped down below other than by way of the “city and tower” [yesod and malchut (commentary Or Yakar)]. They cunningly worked to make the side of impurity dominate on earth and drive away the Master of the earth, malchut of Holiness, from its proper place, and make the powers of impurity dwell upon earth.
“We will make ourselves a name”
This means that they built the corresponding levels (city and tower) on the side of unholiness, by utilizing their knowledge of esoteric matters, which enabled them to use Divine Names to force the ministering angels to do their evil will, as mentioned above.
[From Sitrei Torah, Zohar I, 74b; translation and commentary by Moshe Miller;