Should a barrel containing [wine or oil] that is tevel, be broken [on the Sabbath], one may bring a receptacle and place it under [the barrel]. [By doing so, one is not considered to have nullified the possibility of using the receptacle,] since were one to transgress and separate [the terumah and tithes as required], the produce would be permitted for use..
A receptacle may be placed below a candle to collect the sparks that fall, for [the sparks] have no substance. In such an instance, it is permissible to move the receptacle.
When a beam breaks, we should not support it with a bench or a bed post unless there is ample space [between the beams] and one can remove [the bench or the bed post] whenever one desires, so that one will not nullify a utensil from the possibility of being used.
One may spread a mat over stones or over a beehive on the Sabbath in the summer, [as protection] from the sun, and in the rainy season, [as protection] from the rain, provided that one has no intention of snaring [the bees]. [By doing so, one is not considered to have nullified the possibility of using the receptacle] because one may remove [the mat] whenever one desires.
On the Sabbath one may overturn a basket onto which chicks may climb and descend, since one is permitted to carry [the basket] after they descend. Similar rules apply in all analogous situations.