Heart
The heart means love. A good heart means love to the Lord and to the neighbor, while a hard or stony heart means the love of self or the world -- riches and things. When the psalmist asks the Lord to search his heart, he wants the Lord to see what it is that he loves. And we are what we love. What we eat may form our earthly body, but it's only temporary, what we love forms our spiritual body, beautiful or ugly as we have chosen. It's interesting to note that the first multi-cellular motion of our embryo is the pulsating that starts in a twist of blood vessel that is to become our heart, and the last motion of our natural body is our heartbeat. It is there for all of our natural life. And of course there is a beating heart in our spiritual bodies when we come to put them on.
Arcana Coelestia # 10733
10733. The contents of verse 4 to the end of the chapter are passed over without explanation because every single thing mentioned there has been explained already in Chapters 25-31, where the tabernacle and everything in it, also the altar of burnt offering, and the garments of Aaron and his sons were the subject. For the present chapter merely enumerates the kinds of materials from which these were made.