Whoever pays in advance for anything, let him pay for a specified measure and a specified weight, to be delivered on a specified period of time
‘Abdullāh ibn ‘Abbās (may Allah be pleased with him) reported that when the Messenger of Allah (may Allah's peace and blessings be upon him) came to Madīnah, they used to pay one, two or three years in advance for fruits, so he said: "Whoever pays in advance for anythin…