זוהר שמות — דף רכח ע”א

Betzalel made the hooks so they would rest upon the female elements in the secret of the thousand, which is the complete reckoning. Seven hundred, five, and seventy are all one secret. The beginning of the month of Nissan is tied to the secret of creation, and the Tabernacle was erected on the first of Nissan because it embodies the secret of creation. The entire accounting of the Tabernacle was bound to the secret of holiness.