Thou preventest him - To prevent, from prcevenio, literally signifies to go before. Hence that prayer in the communion service of our public Liturgy, "Prevent us, O Lord, in all our doings, with thy most gracious favor!" That is, "Go before us in thy mercy, make our way plain, and enable us to perform what is right in thy sight!" And this sense of prevent is a literal version of the original word תקדמנו tekademennu . "For thou shalt go before him with the blessings of goodness."
Our ancestors used God before in this sense. So in Henry V.'s speech to the French herald previously to the battle of Agincourt: -
"Go therefore; tell thy master, here I am.
My ransom is this frail and worthless trunk;
My army, but a weak and sickly guard:
Yet, God before, tell him we will come on,
Though France himself, and such another neighbor,
Stand in our way."
A crown of pure gold - Probably alluding to the crown of the king of Rabbah, which, on the taking of the city, David took and put on his own head. See the history, 2 Samuel 12:26-30; (note).
For thou preventest him - Thou goest before him; thou dost anticipate him. See Psalm 17:13, margin. Our word “prevent” is now most commonly used in the sense of “hinder, stop, or intercept.” This is not the original meaning of the English word; and the word is never used in this sense in the Bible. The English word, when our translation was made, meant to “go before,” to “anticipate,” and this is the uniform meaning of it in our English version, as it is the meaning of the original. See the notes at Job 3:12. Compare Psalm 59:10; Psalm 79:8; Psalm 88:13; Psalm 95:2; Psalm 119:147-148; Amos 9:10; see the notes at 1 Thessalonians 4:15. The meaning here is, that God had “anticipated” him, or his desires. He had gone before him. He had designed the blessing even before it was asked.
With the blessings of goodness - Blessings “indicating” goodness on his part; blessings adapted to promote the “good” or the welfare of him on whom they were bestowed. Perhaps the meaning here is, not only that they were “good,” but they “seemed” to be good; they were not “blessings in disguise,” or blessings as the result of previous calamity and trial, but blessings where there was no trial - no shadow - no appearance of disappointment.
Thou settest a crown of pure gold on his head - This does not refer to the time of his coronation, or the period when he was crowned a king, but it refers to the victory which he had achieved, and by which he had been made truly a king. He was crowned with triumph; he was shown to be a king; the victory was like making him a king, or setting a crown of pure gold upon his head. He was now a conqueror, and was indeed a king.