It is good keeping his clothes who is going to swim.

One person goes into the water while another stays on the bank with the swimmer’s clothes. The clothes keeper is involved, but does not swim.

The proverb distinguishes taking part in an undertaking from attending to something for the person who undertakes it. Both have a role, but only one carries out the action in question.

Use the proverb when one person makes an arrangement or attends to an incidental matter while someone else carries out the activity itself. It draws attention to the difference between helping from the sidelines and taking part directly.