Exodus 28:36
And thou shalt make a plate of pure gold, and grave upon it, like the engravings of a signet, HOLINESS TO THE LORD.
Cross-reference
Exodus 29:6 instructs putting the holy crown (the plate) on the turban, directly corresponding to the plate engraved 'Holy to the LORD' here.
Exodus 39:30 records the actual making of the same gold plate with the same inscription, fulfilling the command here.
Leviticus 8:9 describes the actual placing of the gold plate on Aaron's turban during his consecration, fulfilling the command.
Zechariah 14:20 quotes the same 'Holy to the LORD' inscription, extending it to common objects in the Messianic age.
Leviticus 21:6 requires priests to be holy to God, directly paralleling the holiness inscribed on the high priest's turban plate.
Leviticus 21:12 restricts the high priest from leaving the sanctuary due to his consecration, which includes the 'Holy to LORD' plate.
Leviticus 10:3 underscores God's holiness, which the plate's inscription 'Holy to the LORD' symbolizes on the high priest.
Leviticus 19:2 calls all Israel to holiness, while the high priest's plate declares his consecration to the same Holy God.