This phrase may seem harsh and demeaning, but the doctrine is true. This message is to the proud who need to remember that the dust of the earth follows the commands of God better than they do, O how great is the nothingness of the children of men; yea, even they are less than the dust of the earth. For behold, the dust of the earth moveth hither and thither, to the dividing asunder, at the command of our great and everlasting God (Hel 12:7-8).
Brigham Young
"The animal, vegetable, and mineral kingdoms abide the law of their Creator; the whole earth and all things pertaining to it, except man, abide the law of their creation….We tame the animals and make them do our drudgery and administer to our wants in many ways, yet man alone is not tamed—he is not subject to his Great Creator. Our ignorant animals are faithful to us, and will do our bidding as long as they have any strength; yet man who is the offspring of the Gods, will not become subject to the most reasonable and self-exalting principles. How often have we witnessed a faithful animal conveying his master home so drunk that he could not see his way or sit up; yet his faithful animal will plod through mud, shun stumps, trees, and bad places, and land him safely at home." (Journal of Discourses, vol. 9, pp. 246-7 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 205)