And from Abu Sa'id al-Khudri and Abu Hurayrah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) appointed a man over Khaybar, and he came to him with Janyb dates.

The Shaykh : Then he said: "And from Abu Sa'id al-Khudri and Abu Hurayrah (may Allah be pleased with them both):

that the Messenger of Allah, may Allah bless him and grant him peace, appointed a man as an agent in Khaybar

أن رسول الله صلى الله عليه وسلم استعمل رجلا ً على خيبر

Muwatta Malik 31:22

"
This man's name is Suwaid ibn Ghaziyyah, and the ambiguity of the man's name or the clarification of his name generally does not involve a ruling. The obscurity of his name is of the kind that if a person does not know it, it does not harm, and if he knows it, it is an addition of good, but it is not obligatory in the general case and no ruling is contingent upon it. He says: meaning: he appointed him as an agent over Khaybar, a trustee to collect what the Muslims are entitled to from it.
The latter is called Janyb, meaning good dates.
The Prophet (peace and blessings be upon him) said: He asked because the Prophet (peace and blessings be upon him) did not know about these things, nor did he know about all the dates of Khaybar, so he asked. He said: : meaning not all the dates of Khaybar are like this; rather, there are good dates and there are bad dates. : one sa' of this for two sa' of Khaybar dates, and two sa' of this for three sa' of Khaybar dates as well. Which is cheaper, the first transaction or the second?
The student: The first.
Another student: The second.

The Shaykh : There is no god but Allah. Now, be patient, be patient. One sa' for two sa' means one hundred for two hundred. Two sa' for three sa' means two hundred for five hundred, meaning three-fifths. Yes, meaning the hand is three hundred, but the ratio of three hundred to five hundred is three-fifths, and the ratio of that one is one-half. So which is more?
The student: The second.
Another student: The first.

The Shaykh : Now, it does not contradict. If we take the first, one sa' for two sa', how much would two sa' be?
The student: Four.

The Shaykh : Four. So two sa' would be four. And if two sa' were five, what would two sa' be?
The student: Five.

The Shaykh : No, no, it became two sa' for three sa', meaning the sa' would be one and a half sa', meaning a quarter sa' and a half. So the last one is cheaper, cheaper, meaning the bad dates are cheaper, meaning he takes one sa' for one and a half sa'. He comes to take one sa'.
Now, is the cheapness with the good ones or with the bad ones?
The student: No, with the good ones.

The Shaykh : I am asking about the bad ones?
The student: The good ones.

The Shaykh : Now, so we agree, meaning that the good ones are cheaper for the one who took one sa' for two sa', is that right or not?
The student: Yes.

The Shaykh : And conversely, if he took two sa' for three sa'.
Now, the important thing is that they were taking either one hundred percent or two hundred for three hundred, yes, meaning it is cheaper than the first. So the Prophet (peace and blessings be upon him) said: The Messenger (peace and blessings be upon him) said: : This is a prohibitive "no," meaning do not do this action, buying something less with something more of dates. Then he guided him and said: : When he prevented him from the form of riba, he guided him to the form of what is lawful. He said: : The mixed dates are the aggregated, mixed dates, and the general rule is that aggregated, mixed dates are generally bad, because they are from the bad types and are mixed together and not cared for; they are not purified or refined. Buy: meaning purchase, with dirhams Janyb, meaning good dates.
In a wording by Muslim, he said: : meaning return these dates. And this wording contains a great benefit, which is: that even if the owner of the contract is ignorant, if it is forbidden, it must be returned and invalidated, because executing it is a disobedience to Allah and His Messenger, and it considers what the Shari'ah has cast aside. And he said: : He said regarding the scale, what is meant by the scale?
Some scholars said: The meaning of the scale is everything that is weighed.
And some scholars said: The meaning of the scale is gold and silver, because they are weighed: meaning he said with gold and silver just as he said regarding the sale of dates for dates.
So if someone asks: What is the relevance of mentioning the scale in this case, or in this issue?
The answer is: The Messenger of Allah (peace and blessings be upon him), out of the excellence of his teaching, when he mentioned a thing, he mentioned what the questioner might need, even if he did not ask about it. And this is generosity with knowledge. Just as if a poor person asked you: "Give me a shirt," and you gave him a shirt and a turban, then this is generosity with wealth. And adding to the questioner's request is generosity with knowledge. The parallel to this is that the Prophet (peace and blessings be upon him) was asked about the sea, and he said: : although he was not asked about carrion, but whoever rides the sea will need to eat, so the Prophet (peace and blessings be upon him) explained what he might need, because its carrion is pure.
This hadith, as you see, its origin is the sale of dates for dates in unequal amounts. This is its origin, and the Messenger of Allah (peace and blessings be upon him) explained the ruling of this issue with a sufficient and complete explanation.