knowledge of its amount, its removal from ambiguity, and the possibility of its delivery without dispute. Therefore, by whatever amount he estimates it, it is permissible. This differs from the sale of items subject to usury (ribawiyat); for in those, equality is a condition, whether by measure in measurable goods or by weight in weighable goods, and we do not know of this condition applying when one estimates them by a standard other than their original one. Once this is established, all grains are measurable, as are dates, raisins, pistachios, hazelnuts, and salt. The Qadi said: The same applies to oils. He also said regarding ghee, milk, and butter: The Salam contract is permissible for them by measure or weight. However, one should not enter a Salam contract for beestings (liba') except by weight, because it solidifies immediately after being milked, so measuring it by volume is not possible.
Section: If the subject of the Salam contract is something that cannot be weighed on a balance due to its heaviness, such as millstones or large rocks, it is weighed using a boat. The boat is placed in the water, then the item is placed in it, and one observes the point to which it sinks, marking it. Then, the item is removed and replaced with sand or small stones until the water reaches the level it had reached before, and then these are weighed on a scale. Whatever amount they reach is the weight of that item whose weight one intended to know.
Section: It is essential to estimate items measured by length using linear measurement, without any disagreement that we know of. Ibn al-Mundhir said: All scholars we have memorized from are in consensus that a Salam contract is permissible for garments with a known linear measurement.
Section: Anything other than measurable goods, weighable goods, animals, and items measured by length falls into two categories: countable items and others. Countable items are of two types. The first is that which does not vary significantly, such as walnuts, eggs, and the like, so one may enter a Salam contract for them by number. This is the view of Abu Hanifah and al-Awza'i. Al-Shafi'i said: One may enter a Salam contract for them by measure or weight, but not by number, because such items vary and differ, so counting them is not permissible, like watermelons. Our argument is that the variation is slight, and this can be removed by stipulating that they be large, small, or medium-sized, thus eliminating the variation. If some slight variation remains, it is pardoned, just as other variations in measurable and weighable goods are pardoned. It differs from the watermelon, for that is not a countable item, and the variation in it is significant and not controllable. The second type is that which varies, such as pomegranates, quinces, cucumbers, and gourds. The ruling for this is the same as the ruling for non-countable items like watermelons and vegetables, and regarding it, there are two opinions:
