John Calvin Commentary Zechariah 6:14

"And the crowns shall be to Helem, and to Tobijah, and to Jedaiah, and to Hen the son of Zephaniah, for a memorial in the temple of Jehovah." — Zechariah 6:14 (ASV)

Those who think that the crowns were deposited with these four men pervert the meaning of the Prophet. For they were, on the contrary, placed in God’s temple to be a memorial to them.

Therefore, it appears that, as I have already said, they were not required to supply the gold because they excelled all others in piety and holiness. Rather, it was necessary to condemn their lack of faith, since they thought their hope was disappointed when God did not immediately fulfill what He had promised.

Let then these crowns, says the Spirit, be a memorial to them. This means that whenever they look on these crowns, they may check themselves and know that their expectations are very unreasonable. They may also realize that they themselves are too hasty when they wish all prophecies to be accomplished in one day. Furthermore, the whole people may know that they had complained without reason, as these suspended crowns shall be a memorial and a testimony.

So now we see more clearly why the Prophet had been ordered to take gold and silver from these four men: it was so that he might make crowns, which were afterwards to be deposited in God’s temple. Finally, he adds.