The Prophet ﷺ announced the deaths of Zayd, Jafar, and Ibn Rawahah to the people before any news of them had reached them. He said, with tears flowing from his eyes, "Zayd took the banner and was struck down, then Jafar took it and was struck down, then Ibn Rawahah took it and was struck down, until one of the swords of Allah took it up, and Allah granted them victory."
أن النبي ﷺ نعى زيدا وجعفرا وابن رواحة للناس قبل أن يأتيهم خبرهم، فقال: أخذ الراية زيد فأصيب، ثم أخذ جعفر فأصيب، ثم أخذ ابن رواحة فأصيب، - وعيناه تذرفان- حتى أخذها سيف من سيوف الله، حتى فتح الله عليهم.
Bukhari narrated it in the Book of the Virtues of the Companions (3757) and in the Book of Military Expeditions (4262), from Ahmad bin Waqid, who said, Hammad bin Zayd narrated to us, from Ayub, from Humayd bin Hilal, from Anas, and he related it.As for his saying, "until Allah granted them victory," what is meant by "victory" here is that Khalid bin Walid, with his political wisdom, withdrew the Muslim army from the battlefield in such a way that the disbelievers did not perceive the weakness of the Muslims, and they reached Madinah, the city of the Prophet, safely. For this reason it was expressed as a "victory." And Allah knows best.