Dī tē ament!
This is from Conversational Latin. It may or may not be the best translation. But it means, May the gods love you! It is idiomatic. Remember you are saying something like, "may someone" bless you. So there has to be a someone, usually a god or gods or even a person.
Others:
Beātificet deus tē! May the god, a god, God, bless you.
Benedīcat deus tē! May the god bless you.