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.
rub something together
to press two things together and move them back and forth. Sam rubbed his fingers together, indicating that he needed some money before he could continue. Mary rubbed her hands together to get them warmed up.