54 The word צִּיץ (tsits) seems to mean “a shining thing” and so here a plate of metal. It originally meant “flower,” but they could not write on a flower. So it must have the sense of something worn openly, visible, and shining. The Rabbinic tradition says it was two fingers wide and stretched from ear to ear, but this is an attempt to give details that the Law does not give (see B. Jacob, Exodus, 818).
55 Heb “the engravings of a seal”; this phrase is an adverbial accusative of manner.
56 The engraving was a perpetual reminder of the holiness that was due the Lord (Heb “Yahweh”), that all the clothing, the furnishings, and the activities were to come under that description. This corresponded to the symbolism for the whole nation of binding the law between the eyes. It was to be a perpetual reminder of commitment.

In other versions

“You shall make a plate of pure gold and engrave on it, like the engraving of a signet, ‘Holy to the Lord.’

“Make a plate of pure gold and engrave on it as on a seal: holy to the Lord.

“You are to make a pure gold medallion and engrave it, like the engraving of a seal: Holy to the Lord.

“Next make a medallion of pure gold, and engrave it like a seal with these words: Holy to the Lord.

“And you will make a pure gold rosette, and you will engrave on it with seal engravings: “A holy object for Yahweh.”

And thou shalt make a plate of pure gold, and grave upon it, like the engravings of a signet, HOLINESS TO THE LORD.

Public Domain