I've noted a connection between the word of God (or the work of covenant-making) and the hearts of His children. Lately, I've also noticed a connection between these two elements and the Spirit.
Here is an example, as Alma-1 is preparing to baptize at the waters of Mormon:
12 And now it came to pass that Alma took Helam, he being one of the first, and went and stood forth in the water, and cried, saying: O Lord, pour out thy Spirit upon thy servant, that he may do this work with holiness of heart. (Mosiah 18)
Here is another example from the life of Samuel the Lamanite, who receives the voice of the Lord and declares the word to the people according to what the Lord put into his heart:
3 But behold, the voice of the Lord came unto him, that he should return again, and prophesy unto the people whatsoever things should come into his heart.
4 And it came to pass that they would not suffer that he should enter into the city; therefore he went and got upon the wall thereof, and stretched forth his hand and cried with a loud voice, and prophesied unto the people whatsoever things the Lord put into his heart.
5 And he said unto them: Behold, I, Samuel, a Lamanite, do speak the words of the Lord which he doth put into my heart; and behold he hath put it into my heart to say unto this people that the sword of justice hangeth over this people; and four hundred years pass not away save the sword of justice falleth upon this people.
6 Yea, heavy destruction awaiteth this people, and it surely cometh unto this people, and nothing can save this people save it be repentance and faith on the Lord Jesus Christ, who surely shall come into the world, and shall suffer many things and shall be slain for his people. (Helaman 13)
This example is more subtle, but Nephi uses these three elements to bookend the final words of Lehi, as he declares his final words to his posterity:
5 ...Yea, the Lord hath covenanted this land unto me, and to my children forever, and also all those who should be led out of other countries by the hand of the Lord.
6 Wherefore, I, Lehi, prophesy according to the workings of the Spirit which is in me, that there shall none come into this land save they shall be brought by the hand of the Lord. (2 Nephi 1)...
12 And it came to pass after my father, Lehi, had spoken unto all his household, according to the feelings of his heart and the Spirit of the Lord which was in him, he waxed old. (2 Nephi 4)
The final example I'll give is found as Alma and Amulek declare the word among the Nephites:
16 And there was no inequality among them; the Lord did pour out his Spirit on all the face of the land to prepare the minds of the children of men, or to prepare their hearts to receive the word which should be taught among them at the time of his coming—
17 That they might not be hardened against the word, that they might not be unbelieving, and go on to destruction, but that they might receive the word with joy, and as a branch be grafted into the true vine, that they might enter into the rest of the Lord their God. (Alma 16)