Why is 'Honor thy father and thy mother' grouped with the first five commandments?

The command to honor father and mother is grouped with the first five because it includes the phrase "the Lord thy God giveth thee," the connecting link that marks commandments about man's relationship with God. The first five are held together by that phrase, while the last five omit it.

Les teaches that the first five commandments deal with man's relationship with God because they are connected by the phrase "the Lord thy God." Although honoring father and mother seems like a human relationship, the fifth commandment includes the statement "the Lord thy God giveth thee," so he keeps it with the first five. The last five concern man's relationship with man and do not include that connecting link. He emphasizes that those five are held together by that connecting link, the Lord thy God.

Exodus 20:12

Honour thy father and thy mother: that thy days may be long upon the land which the LORD thy God giveth thee.

Why is honoring your father and mother grouped with the commandments about our relationship with God?

Honoring father and mother is grouped with the first five commandments because it contains the same connecting phrase, “the Lord thy God.” Its promise says long days may be given in the land “the Lord thy God giveth thee.” That phrase links it to man’s relationship with God, while the last five omit it.