The Joseph Smith Papers have produced a scanned copy of the 1844 Doctrine and Covenants, that Joseph Smith published just before he died; which includes The Lectures on Faith which are the doctrine portion of the Doctrine & Covenants. See page 5 here of a scanned 1844 (2nd Edition) D&C, to see how the Lectures are the "Doctrine" portion of the D&C in the original LDS Scriptures.
I believe this is the most authoritative source we have for interpreting what Joseph Smith meant in The King Follett Discourse, because Joseph Smith first took part in composing The Lectures on Faith and publishing them as doctrine bound in the Scriptures in 1835. Then he re-published the Lectures on Faith as the doctrine in the canonized Scriptures again in 1844, which was during the same year he said things like "the father had a father" in The King Follett discourse. Therefore, common sense I think says that since he published the Lectures as the doctrine in scripture, then they are clearly the most authoritative source for interpreting what Smith said and likely meant in his sermons that same year in 1844 when he republished the Lectures. Therefore, I don't think that Joseph Smith could have been arguing for a regression of gods, an endless cycle of gods with no beginning, no one divine Source; because in 1844, just months before he died, he again republished The Lecture on Faith and in particular Lecture 2:2 that teaches the doctrine that there is only one Supreme Being or divine Source (i.e. a "First Cause").
We also have a continuity of thought to connect to the 1844 re-publication of the Lectures on Faith, with Joseph earlier mentioning in 1839 that there was one supreme being over-heading a Council of lesser gods in D&C 121:32: where Smith speaks of "the Council of the Eternal God of all other gods before this world was ..." Smith would later describe these lesser gods as Intelligences or spirits in The Book of Abraham, chapter 3. Note that the Divine Council concept is in line with the non-LDS biblical scholar Michael Heiser's scholarship on the biblical Godhead.
Parley P. Pratt in turn dealt with "an infinite regress" and sustained the concept of a "supreme being" (First Cause) by interpreting the "Supreme Being" in Restoration (LDS) Scripture as being the the First God or the "Great God": meaning All Nooma (meaning all divine Spirit-Matter & Energy permeating our Universe) as the ground of all Being, the ontological Source from which is formed the noomatic personages of the Father and Son as glorious noomatic bodies composed of fluid spirit-matter (nooma), which are the Deity (Supreme Being); with the Deity’s Mind (in Lecture 5) referring to the eternal omnipresent Nooma (or spirit-atoms per D&C 131:7) that is governed by the one supreme power, the independent being of Lecture 2.
Thus we see that the first LDS theologians understood that there was an originating divine omnipresent Source sustaining all the other divine Forms in existence. Parley's brother Orson Pratt went on to provide the first footnotes to the post 1876 editions of LDS Scriptures, and in D&C 131: 7 he provides a footnote in that verse that explains the meaning of the Father has "a body of flesh and bones" by drawing the reader back to Lecture 5; thus drawing the first LDS readers to conclude that the Father-Jehovah -- whom Joseph prays to in D&C 109 --- has a body of flesh and bone composed of refined spirit matter (see D&C 130: 22 and 131:7). In other words, years 1876 to 1921 of canonize LDS scripture taught that the Father-Jehovah (as a personage of spirit-matter) is a part of the supreme governing Power's "Godhead," as Lecture 5: 1-2 puts it (emphasis added, words in brackets my own):
[1] In our former lectures we treated of the being, character, perfections and attributes of God. What we mean by perfections, is, the perfections which belong to all the attributes of his nature. We shall, in this lecture speak of the Godhead: we mean the Father, Son and Holy Spirit. [2] There are two personages [Jehovah and Jesus] who constitute [i.e. who form or compose] the great, matchless, governing and supreme power [see Lecture 2:2] over all things ...
The Fifth Lecture goes on to explain that the Sacred Spirit or Mind of the Father, is basically divine nooma (material fluid radiant glory/splendor, the "Great God" as Pratt put it). As the Father is the form of (is constituted by) a noomatic material energy, i.e. the Father is a "personage of spirit, glory, and power" per Lecture 5; meaning He as a form or personage composed of the supreme independent Deity's "glory/nooma and power": as these words signify the Source Deity's omniscient omnipresent Mind emanating and permeating everything as the omnipresent Holy Spirit (i.e. Sacred Nooma), which functions as an omnipresent fluid substance (or liquid spirit-matter), that pervades all space and time like the rays of light (compare D&C 88). In other words, the supreme Deity of Lecture 2.2, expands His omnipresent nature into the noomatically molded/formed personage of Father-Jehovah, which form again is a spiritual/noomatic duplicate of the not yet born earth-born Jesus.
In the 1876 Doctrine and Covenants, in the Table of Contents, it says on page 420 that one of the important items of instructions (from Joseph Smith) on Feb 9, 1843 (which is D&C 130:1) is that "The savior to appear as a glorious personage in the form of a man." D&C 130:1 in turn reads, "When the Savior shall appear, we shall see him as he is. We shall see that he is a man like ourselves." I believe that this is what Joseph Smith was referring to in the King Follet Discourse: that when you see God you will see him in the form of a glorious personage, i.e. in the form of a man composed of spirit-matter as a noomatic body of flesh and bone.
This noomatic body is a twin duplicate of the earth-born Jesus. As we read in Mosiah 7: 27-28:
27 And because he said unto them that Christ was the God, the Father of all things, and said that he [the Father of lights of Lecture 2] should take upon him the image of man, and it should be the image after which man was created in the beginning [ that is the image of Christ]; or in other words, he said that man was created after the image of God, and that God should come down among the children of men, and take upon him flesh and blood, and go forth upon the face of the earth.
In other words, the single independent being, i.e. the noomatic field of fluid energy as the Divine Mind, the Deity (as described in the Lectures on Faith), formed for Himself a "personage of spirit” (the Father-Jehovah per Lecture 5), which is the exact mirror image/copy of the earthborn Jesus per Lecture 5. This is why it says in the 1830 Book of Mormon in Mosiah 15:1-5 (emphasis added):
... God himself shall come down among the children of men, and shall redeem his people. And because he dwelleth in flesh he shall be called the Son of God, and having subjected the [human] flesh to the will of the Father, [Jesus thus] being the Father and the Son [compare D&C 93:12–14, where it says the earth-born Jesus received the fullness of the Nooma over time and not at first as a body of flesh]—The Father [i.e. Jesus is the Father], because he [Jesus] was conceived by the power of God [the supreme independent being and governing power of Lecture 2, conceived Jesus via the Holy Spirit/Fluid Nooma implanting the genome of the Father-Jehovah (the divine DNA of the Father as a personage of spirit) into the womb of Mary to form Jehovah's identical twin body, Jesus]; and the Son, [i.e. Jesus is called the Son] because of the flesh [meaning Jesus is the "Son" on account of him being a molded/stamped copy of the Father-Jehovah's personage of spirit per Lecture 5]; thus becoming the Father and Son—And they are one God [i.e. Jehovah and Jesus are an identical twin genome, thus the one Deity is twin personages yet still one God not two Gods], yea, the very Eternal Father of heaven and of earth. And thus the flesh [Jesus] becoming subject to the Spirit [Nooma], or the Son to the Father, being one God ... [Again, compare D&C 93:12–14]
As mentioned above, in the 1891 Doctrine and Covenants, on page 462, we see that Orson Pratt adds footnote [n] to D&C 130: 22:
The Father has a body of flesh and bones as tangible as man's; the Son also : but the Holy Ghost has not a body of flesh and bones, but is a [n]personage of Spirit. Were it not so, the Holy Ghost could not dwell in us.
Footnote [n] reads: "Lecture 5 : 2, 3." Drawing the reader toward Lecture 5 to interpret this verse. Then on page 463, Orson Pratt provides footnotes to D&C 131:7 directing the reader to his "pamphlet on Absurdities of Immaterialism." Thus providing an explanation for the idea that all spirit-matter and energy has its source from the emanating noomatic glory of the one Head Deity himself, as all things subsist in his expanding glory/slendor, i.e. his noomatic fullness, that literally fills all eternity, as He is:
... the only supreme governor, and independent being, in whom all fulness and perfection dwells; who is omnipotent, omnipresent, and omniscient; without beginning of days or end of life; and that in him every good gift, and every good principle dwells; and that he is the Father of lights ...
(Lecture 2:2).
