In his excellent article, The Higher and Lesser Laws, John Tvedtnes noted:
Joseph Smith provided a wealth of information—particularly in the Joseph Smith Translation of the Bible—on the events that took place at Mount Sinai in the time of Moses, including the following details: (1) God originally intended to make the higher or Melchizedek Priesthood available to all Israel but instead gave a lesser priesthood to the tribe of Levi; (2) this resulted from the unwillingness of the Israelites to accept one of the responsibilities of the higher priesthood, which was to stand in the presence of God; (3) God cursed the Israelites with a carnal law, omitting from the second set of tablets elements of the higher law (including the covenant of priesthood) that had been on the first set of tablets; and (4) the higher law was to be restored through Christ at a later time.
I was reminded of Tvedtnes’ essay which presents the evidence for these teachings from ancient texts while reading the following in a work on Christian ethics which parallels much of Joseph Smith's teachings:
The Apostolical Constitutions (probably dating from the fourth century and compiled in Syria) distinguishes between laws given before the incident of the Golden Calf and those given after it (Exod. 32; see Apostolical Constitutions VI, chs. 19-30). The laws and sacrifices prescribed after the Golden Calf incident are designed to correct Israel’s apostasy and are not binding on Christians. The laws given prior to this incident includes the Ten Commandments (which become increasingly important for the church) and laws of which many begin with the word ‘if’. These laws must be taken seriously by Christians; but they are not necessarily prescriptions. For example, Exodus 20:24 does not say ‘make an altar of earth’ it says ‘if you make an altar, make it of earth’. (John Rogerson, “The Old Testament and Christian ethics” in The Cambridge Companion to Christian Ethics, ed. Robin Gill [Cambridge: Cambridge University Press, 2001], 29-41, here, p. 33).
As an aside, one can find a copy of the Apostolical Constitutions online here.