The second is that the fruit does not pass into the buyer’s risk, nor does the seller cease to be liable for a reduction on account of calamity damage, until it is fully ripe—even if insufficient time has elapsed after ripening for the buyer to harvest it had he wished.
The third is that the fruit does not pass into the buyer’s risk, nor does the seller cease to be liable for a reduction on account of calamity damage, until the customary allowance for delaying its harvest has elapsed after it has fully ripened—the allowance on which both buyer and seller entered into the transaction. This is because, according to them, an established custom has the force of a contractual stipulation. This is a valuable discussion, exhaustively examined and established with the utmost precision. I have neither seen any earlier scholar bring its details together and present them in a clear, considered summary, nor heard it from any later scholar. Allah grants success in reaching what is right and guides by His might.
Section
As for distinguishing what constitutes calamity damage from what does not, the matter may be set out as follows. Calamities fall into two categories:
The first consists of events that are not overwhelming and can be averted and guarded against.
The second consists of overwhelming events that cannot be averted or guarded against.
Anything that is not overwhelming, can be guarded against, and is within one’s power to avert does not constitute calamity damage at all.
As for overwhelming events that cannot be averted or guarded against, these fall into two categories:
The first consists of acts of Allah Most High that are not brought about by any creature.
The second consists of events brought about by legally accountable creatures.
As for acts of Allah Most High that are not brought about by any legally accountable creature, there is no disagreement that they constitute calamity damage for which a reduction must be awarded. An example is wind that causes fruit to fall or spoils it. Allah, Mighty and Majestic, says:
“And in ‘Ād was a sign, when We sent against them the barren wind.” [al-Dhāriyāt: 41] “It left nothing it came upon without reducing it to decayed remains.” [al-Dhāriyāt: 42]