The fourth and final row of the breastplate, according to Targum Pseudo-Jonathan on Exodus 39:13, held chrysolite, onyx, and jasper. Engraved upon them were the names of Zebulun, Joseph, and Benjamin — "enchased and set in gold in their infillings."
Why these three at the end?
Zebulun was the merchant tribe, the one who dwelled on the shore of the sea. Joseph was the viceroy of Egypt, whose bones Moshe himself carried out of the land of bondage (Exodus 13:19). Benjamin was the youngest, the beloved of Jacob, the tribe in whose territory the Temple would eventually stand. Trade, sustenance in exile, and the promise of the sanctuary — three pillars of Israel's survival, fastened in gold.
Enchased in gold
The meturgeman's phrase is careful: the stones were enchased and set in gold in their infillings. Nothing was loose. Nothing could fall out. The tribes were not decoration; they were structural. The breastplate would not hold together without them.
The ancient storytellers noticed something here. If even one stone loosened, the garment would lose its authority. If even one tribe were forgotten, Israel would not be whole. The goldsmith who set the stones was not just a craftsman. He was a guardian of the people's unity, fixing each name so firmly that time could not pry it loose.
Later tradition holds that when the Temple was destroyed, these stones did not perish. They waited. They wait still, the meturgeman implies, for the day when a priest will again wear the names of all twelve tribes over his heart and walk into the Holy of Holies.
The takeaway: the last row is not an afterthought. It is the clasp that closes the whole.