Charles Ellicott Commentary Psalms 132:18

"His enemies will I clothe with shame; But upon himself shall his crown flourish." — Psalms 132:18 (ASV)

Crown (nezer). — As the distinctive use of this word in Israel—by its derivation meaning mark of separation—was for the golden plate, inscribed “Holiness to the Lord,” worn on the high priest’s mitre (Exodus 39:30), we cannot be wrong in seeing here a special allusion to this. This allusion is rendered more probable by the use of the word rendered “flourish” (properly, shine), a cognate to which was the technical name given to this golden plate. (See the reference in Exodus 39:30, mentioned above.) It is also possibly alluded to in Psalm 89:39, the only other place in the Psalms where the word occurs, though as the word is used of the royal crown in 2 Samuel 1:10 and following, the allusion is not certain.

But if the Maccabean hypothesis is correct, the use of the word, instead of the more usual word for “crown,” is interesting. “One relic of the ancient insignia has been preserved, which was probably prized as the most precious of all. It was the golden plate affixed to the turban, inscribed ‘Holiness to Jehovah,’ which was believed to have come down from the time of Aaron, and which, treasured through all the vicissitudes of the Jewish state, was carried to Rome by Titus, and seen there by the great Jewish Rabbi, in the time of Hadrian” (Stanley, J. C. 3:353).