The Messenger of Allah ﷺ visited me during the Farewell Pilgrimage when I was suffering from an illness that had brought me to the brink of death. He mentioned the story of the will, then I said, "Messenger of Allah, will I be left behind after my companions have gone?"He replied, "You will not be left behind to perform any deed by which you seek the face of Allah without it increasing you in rank and elevation. Perhaps you will be left behind so that some people may benefit through you and others may be harmed by you. O Allah, complete my companions' migration for them and do not turn them back on their heels. But the unfortunate one is Saad bin Khawla." The Messenger of Allah ﷺ grieved for him because he died in Mecca.
عادني رسول الله ﷺ في حجة الوداع من وجع أشفيت منه على الموت فذكر قصة الوصية ثم قال: يا رسول الله! أخلف بعد أصحابي؟ قال: إنك لن تخلف فتعمل عملا تبتغي به وجه الله إلا زادت به درجة ورفعة، ولعلك تخلف حتى ينفع بك أقوام، أو يضر بك آخرون. اللهم أمض لأصحابي هجرتهم، ولا تردهم على أعقابهم، لكن البائس سعد بن خولة رثى له رسول الله ﷺ أن توفي بمكة.
Bukhari narrated it in the Book of Battles (4409) and Muslim narrated it in the Book of Bequests (1228), both from Ibrahim bin Saad, who said, our teacher Ibn Shihab narrated to us, from Amir bin Saad, from his father Saad bin Abu Waqqas, and he related it.As for his saying, "You will surely not be left behind only to do deeds," being left behind here means a long life and abundant righteous deeds. As for his saying, "Perhaps you will be left behind until peoples benefit from you," this is one of the miracles, for he lived until Iraq was conquered, and many people entered the religion of Allah through him, and many disbelievers were harmed by him.The remaining of an emigrant in Makkah out of necessity, and dying there, does not nullify the reward of migration. Saad bin Khawlah was among those who emigrated to Abyssinia in the second migration. Musa bin Uqba mentioned that he was among the participants of Badr, and that he died in Makkah during the Farewell Pilgrimage, so the Messenger of Allah ﷺ grieved for him, because he died in the very land from which he had emigrated. For that reason the Prophet ﷺ made a general supplication, saying, "O Allah, complete for my companions their migration and do not turn them back on their heels," meaning that death should not come to him while he is in the land from which they emigrated.