question #1 Sahih al-Bukhari 2240, Book 35, Hadith 3 : What are the conditions for paying in advance for goods to be delivered at a later date in Islamic finance?

The Prophet (ﷺ) came to Medina and the people used to pay in advance the price of dates to be delivered
within two or three years. He said (to them), “Whoever pays in advance the price of a thing to be
delivered later should pay it for a specified measure at specified weight for a specified period.”