The Messenger of Allah ﷺ sent his letter to Kisra with Abdullah bin Huzafa al-Sahmi, instructing him to deliver it to the governor of Bahrain, who would then deliver it to Kisra. When Kisra read the letter, he tore it up.Zuhri, the narrator, said, "I think Ibn al-Musayyab said that the Messenger of Allah ﷺ then supplicated against them, that they be torn apart completely."
أن رسول الله ﷺ بعث بكتابه إلى كسرى مع عبد الله بن حذافة السهمي، فأمره أن يدفعه إلى عظيم البحرين، فدفعه عظيم البحرين إلى كسرى، فلما قرأه مزقه، فحسبت (القائل هو الزهري) أن ابن المسيب قال: فدعا عليهم رسول الله ﷺ أن يمزقوا كل ممزق.
Bukhari narrated it in Maghazi (4424) from Ishaq (that is, Ibn Rahawayh), he said, Yaqub bin Ibrahim narrated to us, he said, my father narrated to us, from Salih (that is, Ibn Kaysan), from Ibn Shihab, who said, Ubaydullah bin Abdullah informed me, that Ibn Abbas informed him, saying, then he mentioned it.Ibn Saad stated definitively that this occurred in the year seven, during the time of the truce, but Bukhari's arrangement indicates that it was in the year nine, after Tabuk. I have already said that Bukhari, may Allah have mercy on him, did not observe chronological order in the chapters of Maghazi.As for his words, "that they be torn apart, utterly torn apart," Allah answered the prayer of His Prophet. He was killed by Ibn Shirawayh on Tuesday night, ten nights into Jumada Awwal, in the year seven.Fath al-Bari (8/127).