Bukhari

Hadith Commentary:
The position of Abdullah ibn Abbas (radi Allahu anhu) is that usury (riba) occurs when there is deferment (i.e., one side is on credit). If cash is exchanged—one dirham for two dirhams—this is permissible. The evidence of Ibn Abbas (radi Allahu anhu) is this hadith:
لا رِبَا إلَّا في النَّسِيئَةِ ("There is no riba except in deferment").
When objections were raised to this fatwa of Abdullah ibn Abbas (radi Allahu anhu), he said: "I do not claim that I found this ruling in the Book of Allah, nor do I say that I heard it from the Messenger of Allah (sallallahu alayhi wa sallam), because at that time I was a child and you were young men. You used to spend day and night in the blessed company of the Prophet (sallallahu alayhi wa sallam)."

Qastallani (rahimahullah) said that now there is consensus (ijma') against the fatwa of Abdullah ibn Abbas (radi Allahu anhu). Some have said that this is to be understood in the case when the commodities are of different kinds, such as silver on one side and gold on the other, or wheat on one side and barley on the other; in such a case, disparity is permissible. Some have said that the hadith "لا رِبَا إلَّا في النَّسِيئَةِ" is abrogated, but abrogation cannot be established merely on the basis of possibility.

In Sahih Muslim, it is narrated from Ibn Abbas (radi Allahu anhu) that there is no riba in a sale that is hand-to-hand (i.e., immediate exchange). Some have also said that Abdullah ibn Abbas (radi Allahu anhu) retracted this statement.

Imam Shawkani states:
"And Hazimi has narrated the retraction and seeking forgiveness of Ibn Abbas when he heard Umar ibn al-Khattab (radi Allahu anhu) and his son Abdullah narrating from the Messenger of Allah (sallallahu alayhi wa sallam) what indicates the prohibition of riba al-fadl (usury of excess). He said regretfully: 'You both have preserved from the Messenger of Allah (sallallahu alayhi wa sallam) what I did not preserve.' And Hazimi also narrated from him that he said: 'That was my opinion, and here is Abu Sa'id al-Khudri (radi Allahu anhu) narrating to me from the Messenger of Allah (sallallahu alayhi wa sallam), so I abandoned my opinion for the hadith of the Messenger of Allah (sallallahu alayhi wa sallam), etc."
That is, Hazimi has transmitted the retraction and seeking forgiveness of Ibn Abbas (radi Allahu anhu) when he heard the statement of the Messenger of Allah (sallallahu alayhi wa sallam) regarding the prohibition of this sale from Umar ibn al-Khattab (radi Allahu anhu) and his son. He regretfully said: "You people preserved the statement of the Messenger, but alas, I could not preserve it." And according to Hazimi, he also said: "What I said was only my opinion, and after hearing the hadith of the Prophet (sallallahu alayhi wa sallam) from Abu Sa'id al-Khudri (radi Allahu anhu), I abandoned my opinion."

Integrity also demands that when the clear texts of the Qur'an and hadith are presented, no opinion or analogy should be considered as proof, and the Book and the Sunnah should be given precedence. Even if the opinions of the great Imams of the religion appear to be contrary to the clear texts, then with utmost respect and reverence, the Book and the Sunnah should be given precedence over opinions.

The Imams of Islam—Imam Abu Hanifah, Imam Shafi'i, Imam Malik, and Imam Ahmad ibn Hanbal (rahimahumullah)—all have stated that our fatwas should be presented before the Book and the Sunnah; if they are in agreement, then accept them. If they appear contrary, then give precedence to the Book and the Sunnah.

The Imam of India, Shah Waliullah Muhaddith Dehlawi (rahimahullah), has quoted such statements of the Imams in several places in his esteemed book "Hujjatullah al-Baligha." But, alas, a large segment of the Ummah is such that it is severely afflicted with rigidity within its own circle of allegiance, and is not prepared to accept any verse of the Noble Qur'an or any clear, explicit hadith of the Prophet (sallallahu alayhi wa sallam) that goes against its supposed school of thought.

The late Hali has said regarding such people:
Forever there is resentment in the hearts of the people of research,
They think following hadiths causes harm to the religion,
Their entire practice is based on fatwas,
Every opinion is considered a substitute for the Qur'an,
Neither faith remains, nor Islam remains,
Only the name of Islam remains.

Hadith Commentary:
When there is an exchange between items of the same kind, it must be equal for equal and hand to hand. However, the position of Abdullah ibn Abbas (radi Allahu anhu) was that it is permissible to sell one dinar for two dinars if it is hand to hand. According to him, usury (riba) only occurs when there is delay from one side.

When Abu Sa‘id al-Khudri (radi Allahu anhu) met him, he said:
Ibn Abbas! You should fear Allah. How long will you continue to make people consume usury? Then he narrated this hadith: The Messenger of Allah (sallallahu alayhi wa sallam) said:
“It is permissible to sell dates for dates, wheat for wheat, barley for barley, gold for gold, and silver for silver, when it is equal for equal and hand to hand. Whoever takes more has engaged in usury.” Upon hearing this Prophetic hadith, Ibn Abbas (radi Allahu anhu) said:
Abu Sa‘id! May Allah grant you Paradise! You have reminded me of something I had forgotten. I seek forgiveness from Allah and turn to Him in repentance.
After this, Ibn Abbas (radi Allahu anhu) would prohibit it very strictly.
(al-Mustadrak lil-Hakim: 2/43)

Since the position of Ibn Abbas (radi Allahu anhu) was contrary to other authentic ahadith, he retracted his view. However, the hadith narrated from Ibn Abbas (radi Allahu anhu) is also authentic. The following interpretations have been made of it:
➊ There is no usury more severe than that which is in deferred payment.
➋ What is meant is the exchange of different kinds of commodities, where usury only occurs in deferred payment, and in such cases, disparity is permissible.

And Allah knows best.