A stone that is in a gourd-shell, if water can be drawn with it without its falling out, we may draw [water] with it; and if not, we may not draw [water] with it. A branch that is tied to a pitcher, we may draw water with it on the Sabbath.

A window shutter, R’ Eliezer says: When it is fastened and suspended, we may shut [the window] with it; and if not, we may not shut [the window] with it. But the Sages say: In either case we may shut [the window] with it.