"To Winterfell we pledge the faith of Greywater,” they said together.
“Hearth and heart and harvest we yield up to you, my lord. Our swords and spears and arrows are yours to command. Grant mercy to our weak, help to our helpless, and justice to all, and we shall never fail you.”
“I swear it by earth and water,” said the boy in green.
“I swear it by bronze and iron,” his sister said.
“We swear it by ice and fire,” they finished together."
House Reed, A Clash of Kings