For my soul delighteth in the scriptures, and my heart pondereth them.
Behold, my soul delighteth in the things of the Lord; and my heart pondereth continually upon the things which I have seen and heard.

-thus Nephi.

We Mormons say that the soul refers to the combination of the body and the spirit. In some contexts, maybe so. There are however plenty of scriptures where the word soul clearly is not referring to the union of the body and the spirit. This scripture is probably one of them. But even so, it is pleasant to imagine Nephi physically thrilled by the scriptures. C.S. Lewis once talked about spiritual joy spilling over into the flesh. It happens. The spirit and the body are one. To affect the part is to affect the whole.

Nephi says he ponders with his heart. Usually I think of pondering as a mental activity. Nephi did not. He pondered emotionally, with his whole being.