Abu Dawud said: Likewise, al-Firyabi and Abu Ahmad narrated it from Sufyan, and they agreed with him in the text. Abu Ahmad—and he erred—said "from Ibn 'Abbas" in place of Ibn 'Umar. And al-Walid ibn Muslim narrated it from Hanzalah, who said: "The weight is the weight of Medina, and the measure is the measure of Mecca."

============================================

...from the people of these lands is carried according to the custom of his land and the practice of his people; it is not transferred from it, nor is it carried to anything other than it. And they are not like dirhams and dinars, regarding which people were held to a single standard and an equal ruling...

Then he said: As for his statement, "The measure is the measure of the people of Medina," it refers to the sa' upon which the obligation of expiations depends, by which the charity of Fitr is required to be paid, and by whose standard the estimation of maintenance payments and what is analogous to them is made. And God knows best.

People have different sa's: the sa' of the people of the Hijaz is five and one-third ratls by the Iraqi standard. The sa' of the people of the House—according to what the Shi'a leaders mention—is nine and one-third ratls, and they attribute it to Ja'far ibn Muhammad. The sa' of the people of Iraq is eight ratls, and it is the sa' of al-Hajjaj, by which he priced the people of the markets. And when Khalid ibn 'Abd Allah al-Qasri took charge of Iraq, he doubled the sa', making it reach sixteen ratls.

Thus, when it comes to matters of transactions, we carry the Iraqi sa' upon the well-known, customary sa' among the people of its lands, and the Hijazi upon the sa' known in the lands of the Hijaz, and likewise each people of a land according to the custom of its people. But when it comes to the Shari'a and its rulings, it is the sa' of Medina. That is the meaning of the hadith and its proper interpretation in my view. And God knows best.

We say: The amount of what has been mentioned above of measures and weights, in contemporary units, is as will follow:

As for the dirham, it equals 2.975 grams.
As for the dinar, it equals 4.25 grams.
The qirat equals 0.2475 grams, if we consider the mithqal divided into twenty-two qirats.
The habba equals 0.059 grams of gold.
Ten dirhams equal (2.975 × 10) = 29.75 grams.
The Baghdad ratl equals 408 grams, and accordingly the Baghdad sa' equals 2176 grams, and the rest of the sa's are calculated on the basis of the Baghdad ratl.