Sahih Muslim | Book 9 | Chapter 2

Narrated by Ibn 'Abbas (Allah be pleased with them)
Ibn 'Abbas (Allah be pleased with them) reported that the (pronouncement) of three divorces during the lifetime of Allah's Messenger (may peace be upon him) and that of Abu Bakr and two years of the caliphate of Umar (Allah be pleased with him) (was treated) as one. But Umar b. Khattab (Allah be pleased with him) said: Verily the people have begun to hasten in the matter in which they are required to observe respite. So if we had imposed this upon them, and he imposed it upon them.

Narrated by Abu Sahba'
Abu Sahba' said to Ibn 'Abbas (Allah be pleased with them): Do you know that three (divorces) were treated as one during the lifetime of Allah's Apostle (may peace be upon him), and that of Abu Bakr, and during three (years) of the caliphate of Umar (Allah be pleased with him)? Ibn Abbas (Allah be pleased with them) said: Yes.

Narrated by Abu al-Sahba'
Abu al-Sahba' said to Ibn 'Abbas: Enlighten us with your information whether the three divorces (pronounced at one and the same time) were not treated as one during the lifetime of Allah's Messenger (may peace be upon him) and Abu Bakr. He said: It was in fact so, but when during the caliphate of 'Umar (Allah be pleased with him) people began to pronounce divorce frequently, he allowed them to do so (to treat pronouncements of three divorces in a single breath as one).