valid according to those who maintain that making a sale conditional upon a condition is invalid. This is a matter of scholarly disagreement, but the correct view is that a contract may be made conditional upon a condition.

His statement, “and sale by throwing”: this is derived from nabdh (throwing), such as when the buyer says to the seller, “Whichever garment you throw to me is ten.” In this case, the seller will choose the least valuable garment possible, so it is unknown. He may throw him a garment worth ten, while the buyer expects him to throw a garment worth one hundred. The evidence for its invalidity is both general and specific.

The general evidence is the hadith of Abu Hurayrah, may Allah be pleased with him: the Prophet, may Allah’s peace and blessings be upon him, prohibited sales involving excessive uncertainty (1). This hadith is a major legal principle.

The specific evidence is that the Messenger of Allah, may Allah’s peace and blessings be upon him, prohibited sale by touch and sale by throwing (2).

Sale by pebble is similar and is likewise invalid. It takes two forms:

The first form is for him to say, “Throw a pebble; whatever it lands upon is ten.” He then throws the pebble, and it lands on an empty matchbox, which is thus sold for ten. Then he throws another pebble, and it lands on jewelry encrusted with gemstones worth thousands. This involves ignorance.

The second form is for him to say, “Throw this pebble, and whatever distance it reaches across the land shall be yours for such-and-such an amount.” This too is unknown, because throwers differ: a vigorous and strong man throws farther, whereas another man