And upon these I write the things of my soul, and many of the scriptures which are engraven upon the plates of brass. For my soul delighteth in the scriptures, and my heart pondereth them, and writeth them for the learning and the profit of my children.
(2 Nephi 4:15)
I don’t think any commentary is necessary on this verse.
I can’t say I like the title “the Psalm of Nephi” that some people have given the latter part of this chapter (though I can’t think of any rational objections). But the chapter itself contains many passages in which my soul “delighteth” or that my heart “pondereth”:
Nevertheless, notwithstanding the great goodness of the Lord, in showing me his great and marvelous works, my heart exclaimeth: O wretched man that I am! Yea, my heart sorroweth because of my flesh; my soul grieveth because of mine iniquities.
I am encompassed about, because of the temptations and the sins which do so easily beset me.
And when I desire to rejoice, my heart groaneth because of my sins; nevertheless, I know in whom I have trusted.
(2 Nephi 4:17-19)
O then, if I have seen so great things, if the Lord in his condescension unto the children of men hath visited men in so much mercy, why should my heart weep and my soul linger in the valley of sorrow, and my flesh waste away, and my strength slacken, because of mine afflictions?
And why should I yield to sin, because of my flesh? Yea, why should I give way to temptations, that the evil one have place in my heart to destroy my peace and afflict my soul? Why am I angry because of mine enemy?
Awake, my soul! No longer droop in sin. Rejoice, O my heart, and give place no more for the enemy of my soul.
Do not anger again because of mine enemies. Do not slacken my strength because of mine afflictions.
Rejoice, O my heart, and cry unto the Lord, and say: O Lord, I will praise thee forever; yea, my soul will rejoice in thee, my God, and the rock of my salvation.
(2 Nephi 4:26-30)