Paraphrasing -
When the Saints came to the Salt Lake Valley and began building the beautiful House of the Lord, that is the Salt Lake Temple, they thought their persecution was over. They built the foundation of the temple and they thought it was strong. Then, soldiers of the army of the United States showed up to forcibly install a governor to run the state. Because President Brigham Young was unsure of the army's intent and motives, he ordered the foundation of the temple to be buried.
When the army dispersed, President Young had the foundation excavated and inspected. Upon the inspection, it was found that the sandstone foundation had cracked in places causing it to be incapable of supporting a magnificent structure. The foundation needed to be replaced. It was replaced with stones of granite....uncrackable, strong, unbreakable and firm. Indeed, how firm a foundation.
Elder Dieter F. Uchtdorf, General Conference, Saturday Afternoon Session, October 2020
As we go through the various tasks of our day, particularly tasks of a faith building endeavor, like studying the scriptures, we have the feeling that our foundation is strong. But... then the Lord corrects us and keeps us humble.
He allows and sometimes sends forth humbling circumstances our way. In the form of trials and challenges, or heartache and sorrow, or disease and sickness.
Then, as we inspect our lives and our foundations, we realize that our foundation isn't as strong as we thought. We find cracks or even holes. So, we go about strengthening our foundations, even replacing them as needed. Then we do it again, and again, until our foundations are indestructible.
"And the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock."
- Matthew 7:25