When God told man to honor their father and mother (Deuteronomy 5:16), He attached the specific provision that doing so would allow their “days to be prolonged” and that it would “go well with you on the land.”
The idea behind this is straightforward: Honor for your parents extends to honor for other authority figures, including God. If that’s true, though, then why does God use almost the exact same phrase when He says not to take a mother bird with their young?
Technically though, the phrase is inverted. Instead of “days be prolonged” and “go well with you on the land,” he says in Deuteronomy 22:7 that “it may be well with you” and that “you may prolong your days.” A statement that’s that similar denotes a connection between the two ideas.
And maybe that’s part of the reasoning behind this law. The central idea behind both verses is that doing a certain action (honoring your parents; not taking mother with young) extends your life in the land, and extends it with good.
In one respect, honoring your parents establishes a set standard of authority in the land—one that goes all the way up to God. Who, in turn, continues to bless His people.
The second one about birds is more simplistic: If you take a mother and the young, you deplete the natural resources faster. You eliminate a family line, and possibly drive that species into extinction. What kind of existence in the land is that?
Other people will point to this law as preventing outright ruthlessness in the land, as if killing the mother and the child is especially harsh. But if I can speak frankly, I don’t know how sparing the mother and killing the child is much better. Most mothers I know would gladly trade places rather than bear that kind of horror.
Instead, I think this law, just like the ones that follow it, is more practically based. Don’t do this, don’t do that—not because it necessarily dishonors or honors something, but because they are the nuts and bolts of living in a land that stays prosperous.