intervene between (multiple people)

To intercede between multiple people. Luckily, the teacher intervened between Mark and Mike before a fight broke out. In an attempt to deescalate the situation, I intervened between the two arguing parties. I wasn't about to intervene between those people—didn't you see that some of them were armed?

rub (multiple things) together

To exert pressure on two or more things while moving them in continuous contact with one another to create friction. Starting a fire isn't just as easy as rubbing two sticks together. She put soap in her hands and rubbed them together to form a lather.