"Search for the Treasure The word of God is to be our study. We are to educate our children in the truths found therein. It is an inexhaustible treasure; but men fail to find this treasure because they do not search until it is within their possession. Very many are content with a supposition in regard to the truth. They are content with a surface work, taking for granted that they have all that is essential. They take the sayings of others for truth, being too indolent to put themselves to diligent, earnest labor, represented in the word as digging for hidden treasure. But man's inventions are not only unreliable, they are dangerous; for they place man where God should be. They place the sayings of men where a “Thus saith the Lord” should be. COL 109"
"Again, the kingdom of heaven is like unto treasure hid in a field; the which when a man hath found, he hideth, and for joy thereof goeth and selleth all that he hath, and buyeth that field."
Both passages use the metaphor of hidden treasure to represent the value and effort required to find spiritual truth. The EGW passage directly references the idea of 'digging for hidden treasure,' echoing the parable in Matthew 13:44.
"If thou seekest her as silver, and searchest for her as for hid treasures;"
The EGW passage directly uses the metaphor of searching for hidden treasure to describe the diligent study of God's word, which is precisely the imagery used in Proverbs 2:4. The connection is clear and intentional.