“The king must not acquire many horses”
But the king must not acquire many horses for himself or send the people back to Egypt to acquire more horses. (Deuteronomy 17:16 BSB)
What it sounds like today
An oddly specific rule about royal livestock.
The cultural key
Almost alone in the ancient world, Israel's law placed the king under the law rather than above it. Horses meant chariots and military power (and trade with Egypt, the house of slavery); the following verses forbid many wives (foreign alliances and the idolatry they brought) and hoarding silver and gold. The king was to write out and read the Torah daily instead. The tragedy is that Solomon violated each prohibition in turn, amassing horses from Egypt, seven hundred wives, and legendary gold, and those very excesses fractured the kingdom.
Recovered meaning
Israel's monarchy was a constitutional one: even the king answered to God's law and was barred from the usual trappings of absolute power. The rules read like a prophecy of Solomon's downfall, ruined by the horses, wives, and gold he was told to refuse.