On shabbos I went to go hear a shiur in the late afternoon. There were more people than usual because of the shabbaton that the shul was having. After the shiur and mincha, it was time for shalosh seudos. Usually they have enough chairs in the hall, but since there was a lot more people there, they had to bring in a bunch of chairs from the shul to the hall. Before we went, the rabbi said that instead of bringing one for ourselves, what we should do is we should each bring one for someone else. And that's what we did.