The word “for” tells the reader that what follows is the reason for this strange command. It is because the land has committed great whoredom by forsaking the Lord.
This is the first indication in the book that Hosea’s marriage and children are to symbolize the relationship between God and his people.
2 When the LORD first spoke through Hosea, the LORD said to Hosea, “Go, take to yourself a wife of whoredom and have children of whoredom, for the land commits great whoredom by forsaking the LORD.”