Deuteronomy 33:19
They shall call the people unto the mountain; there they shall offer sacrifices of righteousness: for they shall suck of the abundance of the seas, and of treasures hid in the sand. They shall call the people unto the mountain; there they shall offer sacrifices of righteousness: for they shall suck of the abundance of the seas, and of treasures hid in the sand.
The blessing pictures the promised land as it would be under God's favor, rich in blessings of every kind. Its landscape would be fruitful, showing divine bounty in the fertility of the country itself. Its natural riches would also extend to what the seas provide, with the abundance of the seas drawn in for sustenance and wealth. Even the sand would hold its share of provision, concealing treasures to be brought forth for the people's good.