We are to rejoice in God's Word in the same way we would rejoice in money and riches. If I were to give a little boy $20, wouldn't his face light up? Wouldn't a smile stretch from ear to ear? How would he react? How would he treat it? That is how we should treat the Word of God, with all rejoicing.
I liked The Treasury of David's comparison of God's Word and riches:
"Riches are desirable as the means of procuring the necessaries of life; but God's testimonies supply the necessities of the soul.
Riches are desirable as a means of procuring personal enjoyment; but God's testimonies produce the highest joy.
Riches are desirable as a means of attaining personal improvement; but God's testimonies are the highest educators.
Riches are desirable as a means of doing good; but God's testimonies work the highest good."
Spurgeon also says this:
"He [David] compared his intense satisfaction with God's will with that of a man who possesses large and varied estates, and the heart to enjoy them. David knew the riches that come of sovereignty and which grow out of conquest; he valued the wealth which proceeds from labour, or is gotten by inheritance: he knew "all riches." The gracious king had been glad to see the gold and silver poured into his treasury that he might devote vast masses of it to the building of the Temple of Jehovah upon Mount Zion. He rejoiced in all sorts of riches consecrated and laid up for the noblest uses, and yet the way of God's word had given him more pleasure than even these. Observe that his joy was personal, distinct, remembered, and abundant. Wonder not that in the previous verse he glories in having spoken much of that which he had so much enjoyed: a man may well talk of that which is his delight."
So my question for you is, do you rejoice in the testimonies of God as much as all riches?