The great importance and significance of the Mitzvah to honor parents is seen in the fact that it is part of the Decalogue, the core of the Torah.
[This is not to be understood as an essential differentiation between the ten Mitzvos of the Decalogue and the remaining 603 Mitzvos in the other part of the Torah. The whole Torah, all 613 Mitzvos, emits from the same source, i.e. from G-d, and no essential distinction can therefore be made between one part and another. Even so, the Decalogue has the distinction of having been proclaimed by the public Divine Revelation at Sinai, while the other commandments were transmitted via Moses. This in itself would still not offer an essential difference between the commandments of the Decalogue and the other Mitzvos. However, the Decalogue is not only a code of ten specific Mitzvos, but moreover, a statement of ten comprehensive principles which imply and comprise all 613 Mitzvos of the Torah. (See Zohar II:90b and 93b; Numbers Rabba 13:16 and 18:21)
In fact, several works have been composed which show how the 613 Mitzvos are to be grouped into these ten principal categories (See Rashi on Exodus 24:12; "Commentary on Shir Hashirim" attributed to Nachmanides, end.) Thus, there is some special significance even to the specific precepts of the Decalogue.]
Two commandments in the Torah
[Maimonides (and others) enumerates in addition to these commandments also three prohibitions:
a) not to curse one's father or mother; b) no to smite one's father or mother; and c) that a son shall not rebel against the authority of his father or mother.
See Sefer Hamitzvos II:218, 219 and 195, and Hilchos Mamrim ch 5ff.; note also the commentaries ad loc.]
Dealing with the duties and the relationship of the child to its parents:
a) Honor your father and your mother, (Exodus 20:12; Deut. 5:16)
b) Ye shall fear every man his mother and his father (Levit.19:3)
[In the matter of honor due to parents, the father is mentioned first; in the matter of reverence due to them, the mother is mentioned first. From this we infer that both are to be equally honored and revered. [Kerrithoth 6:9 (28a)] Thus, whatever is said of one parent applies equally to the other parent.]
