"I entreat you who have long professed the faith and who still pay outward homage to Christ: Do not deceive your own souls. It is the whole heart that Jesus prizes. The loyalty of the soul is alone of value in the sight of God. “If thou hadst known, even thou, at least in this thy day, the things which belong to thy peace!” “ Thou, ... even thou ”—Christ is at this moment addressing you personally, stooping from His throne, yearning with pitying tenderness over those who feel not their danger, who have no pity for themselves. 5T 73.1"
"Saying, If thou hadst known, even thou, at least in this thy day, the things which belong unto thy peace! but now they are hid from thine eyes."
The EGW passage directly quotes Luke 19:42 and builds upon it, applying it to the reader. The connection is undeniable.