Tehillim 118:19 Kabbala: Zohar

בְּרֵאשִׁית. Rabbi Chiya opened the discussion with the verse, "The fear of Hashem is the beginning of wisdom; good understanding have all they who do His commandments; His praise endures forever" (Ps. 111:10). Of the phrase, "the beginning of wisdom," this verse have read 'the fear of Hashem is the end of wisdom,' because the fear of Hashem (is the secret of Malchut), which is at the end of Chochmah! She (Malchut) is the beginning or the first stage that opens the entrance to the level of the supernal Chochmah (Wisdom). So it is written, "Open to me the gates of righteousness" (Ibid. 118:19), "this is the gate to Hashem" (Ibid. 20). Assuredly, if he does not enter this gate, he shall never reach the Supernal King, because He is exalted, hidden, and concealed, and has made gates for Himself, one behind the other.

And she [Tamar] sat on Petach Eynayim [the entrance to the eyes] (Gen. 38:14) - Just as you say "and he [Avraham] sits at the entrance [petach] of the tent" (Gen. 18:1), and it is written "And Ad-nai passed over the entrance [petach]" (Ex. 12:23), and it is written "open [pitchu] for me the gates of righteousness etc" (Ps. 118:19) [meaning] that all eyes of the world turn to that opening. [...]