Ruling on selling dates, salt, and wheat on credit

Question: To the honorable, learned father, Shaykh Abdul Aziz ibn Abdullah ibn Baz (may Allah preserve you and protect you). Peace be upon you, and Allah’s mercy and blessings. After that:
We are young men from the al-Darraj district in Yemen:
We submit this letter to you, containing two important questions, and we ask you to provide written answers to them so that we may present them to our families—may Allah guide you to righteousness and correctness in all your words and deeds.

First question: We have commercial shops that sell to people on credit, and among what they sell on credit are wheat, dates, and salt. What is the ruling on this transaction?

Answer: And upon you be peace and the mercy of Allah and His blessings. As for what follows:
In answer to the first question: regarding the sale of wheat, dates, and salt on credit, there is no harm in that, provided the item sold is known, the price is known, and the term is known—if it is deferred—and likewise if the item sold is a visible batch of dates, salt, wheat, or the like.