“These are the chronicles of Jacob: Joseph was 17 years old.”
The Sages said, “Everything that happened to Jacob happened also to Joseph.” This is also true in the spiritual worlds, where Jacob represents the process of Zeir Anpin's maturing, and becoming wise and kind.
Jacob went down to Egypt with 70 souls. By then his part in Zeir Anpin amounted to Kindness, Strength, and two-thirds of Beauty, the hidden qualities of Zeir Anpin. The gematria of the name of God, יהוה, taken two times is 26 * 2 = 52. Add to this two-thirds, roughly 18, and you get 70.
The number of year that they were going to spend in Egypt is 430. This number is the gematria of the name of God אלהים, taken 5 times. These years were necessary for Zeir Anpin's maturing. The Understanding that Zeir Anpin was going to achieve there is represented by all possible permutations of this name of God, אלהים. Since one can take any of the 5 letters as the first one, this gives 5 possibilities to start. The next letter is one of 4, and this leads to 5 * 4 = 20 permutations. Then comes 3, then 2, and the result is 5*4*3*2*1=120, or 5 factorial (denoted as 5!). This is hinted to in the phase, “You placed him a little lower (מעט) than the angels (אלהים)”. The gematria of "a little lower" (מעט) is 119.
The growth of Zeir Anpin's Understanding begins to control his whole body, by going down through his neck, and pushes the non-rectified parts to the lowest areas of Victory, Glory, and Foundation, which are represented by Pharaoh's three Princes: the Prince of Wine, the Prince of Bread, and the Prince of Meat (Potifar). At the same time the lower levels reflect the higher ones, and the Prince of Wine (Wisdom) was returned to his place – since Wisdom is internal and is not directly under the control of man. However, the Prince of Bread was hung (תלה), literally, “brought up” - since Understanding and Judgment require more perfection and are brought about through man's work.
Art: Leonardo Da Vinci - Muscles of the neck and shoulders