-What advice did Soda have for Ponyboy and Darry? What agreement did the brothers make?

Soda confesses how upset it makes him when Darry and Ponyboy fight. He says that all they have is each other, and that they need to stick together in order not to end up the way Dally was before he died, hardened. Darry and Ponyboy agree not to fight anymore, suddenly realizing how much they accidentally have been hurting Soda. The brothers race back to the house.