Thou shalt make a plate of pure gold. The plate, though a mere ornament of the mitre, was, at once, its most conspicuous and its most significant feature. Placed directly in front, right over the forehead, and probably of burnished gold, it would attract universal attention, and catch the eye even more than the breast-plate.
Its position made it "the culminating point of the whole priestly attire" (Kalisch)—and its inscription gave to that position extraordinary force and significance. For it taught that "holiness to the Lord" is the very highest crown and truest excellence of religion—that to which all ceremonial is meant to conduce—that without which all the paraphernalia of worship must ever be in God's sight a mockery.
It set this truth conspicuously before the eyes, and was apt to impress it upon the hearts of all. It taught the high priest himself not to rest upon outward forms, but to aim in his own person, and teach the people to aim continually, at internal holiness.
The extreme importance of this, causes the putting forward at once of the plate and its inscription before any account of the "mitre" is given.