How could David enter the congregation of the Lord when he was descended from Ruth the Moabitess?

I want to ask a question about Ruth the Moabitess and King David. >Deuteronomy 23:3 An Ammonite or Moabite shall not enter into the congregation of the LORD; even to their tenth generation shall they not enter into the congregation of the LORD for ever: And Ruth was a Moabitess, AND, the great grandmother of King David. >Ruth 1:22 So Naomi returned, and Ruth the Moabitess, her daughter in law, with her, which returned out of the country of Moab: and they came to Bethlehem in the beginning of barley harvest. MY QUESTION IS Logically, how can David be lawfully accepted 'into the congregation of the Lord' (let alone, be selected by the LORD to be King of Israel,) when he was clearly only 3 generations away from Moab heritage? I am searching for any scriptural explanation, which would justify David being accepted 'into the congregation of the Lord', taking into account the clear "even to their tenth generation" prohibition of Deuteronomy 23:3. And, doesn't Jewish heritage follow the mother?