Shavuot - Ruth
In Megillat Ruth, Naomi insists that her daughters-in-law return to their homes as they have no reason left to remain with her. Orpah went home, but Ruth insisted on staying with Naomi. She said, in what has become famous, "Where you go, I go, Where you sleep, I shall sleep. Your nation is my nation and your God is my God, etc..". In 1:18 we see Naomi's response. The passuk says, "She saw that Ruth was insistent on remaining with her and she stopped talking with her."
Naomi saw that Ruth was insistent on remaining with her as a convert to Judaism. She realized it is pointless to continue arguing about it as Ruth was adamant. She realized there is no point in beating a dead horse. If Ruth really wants to come along and be Jewish, so be it.