Two passages continualy come to mind when I think on the word. Numbers 32:23 and 1 Kings 8:38.
We all know the depths of our heart (to a greater or lesser degress) and that when our heart is exposed, much pain is experienced. The Holy Spirit said we are to protect our heart (Prov. 4:23), but that does not mean we are not to allow others to see us as we are; it means that our best protection is when the word is laid up in the heart (Col. 3:16). Thus, when (if) the heart is exposed, what will be seen?