זוהר שמות — דף קד ע”ב

Boaz is Ibzan, the primordial father who made no change, thus preserving the purity of David's lineage without admixture. Judah was chosen from beginning to end above all brothers: he alone bears the title "you" at the level of royalty. His sons are sons of the lion without change, and from him alone proceeds the royal chain. The mystery of levirate marriage teaches that reincarnation passes through brothers, and here all his brothers acknowledge that royal sovereignty passes only through Judah. The deaths of Er and Onan and Judah's strength in fathering Peretz and Zerakh illustrate the lion's power to build and complete.