Urwah bin al-Zubayr (may Allah have mercy on him) mentioned those who went to the Battle of Badr and those who did not, (saying) that the Messenger of Allah (peace and blessings be upon him) assigned a share to those present at the battle, and among those who were absent he gave a share to Uthman bin Affan bin Abi al-As bin Umayyah bin Abd Shams (may Allah be pleased with him); he had stayed behind in Madinah because of the illness of his wife Ruqayyah (may Allah be pleased with her). He (peace and blessings be upon him) gave him his share, and he said: "O Messenger of Allah (peace and blessings be upon him), and my reward?" He (peace and blessings be upon him) said: "Your reward too." And Talhah bin Ubaydullah bin Uthman bin Amr bin Ka'b (may Allah be pleased with him) was in Syria; he came to the Messenger of Allah (peace and blessings be upon him) and spoke to him, so he (peace and blessings be upon him) gave him a share as well. He asked about the reward, and he (peace and blessings be upon him) said: "You will receive your reward too."
And Sa'id bin Zayd bin Amr bin Nufayl (may Allah be pleased with him) also came from Syria after he (peace and blessings be upon him) had returned to Madinah, and the Prophet (peace and blessings be upon him) gave him a share, and about the reward too he said: "You will receive it." These three were from the Muhajirun. From the Ansar there was Abu Lubabah (may Allah be pleased with him), who went out with the Messenger of Allah (peace and blessings be upon him) towards Badr; he (peace and blessings be upon him) had made him governor of Madinah. He (peace and blessings be upon him) gave him a share along with the people of Badr. He (peace and blessings be upon him) had also sent al-Harith bin Hatib (may Allah be pleased with him) back to Madinah, and he gave him a share as well. Asim bin Adi (may Allah be pleased with him) also set out, but he (peace and blessings be upon him) sent him back and gave him a share as well. He also gave a share to Khawwat bin Jubayr bin al-Nu'man (may Allah be pleased with him) along with the people of Badr, and to al-Harith bin al-Simmah (may Allah be pleased with him), who had been injured at al-Rawha', he (peace and blessings be upon him) gave a share as well. All of them were also mentioned by Muhammad bin Ishaq bin Yasar and Musa bin Uqbah (may Allah have mercy on them both), except that he did not mention al-Harith bin Hatib (may Allah be pleased with him) being sent back to Madinah.
Imam al-Shafi'i (may Allah have mercy on him) said: He (peace and blessings be upon him) gave them from his own wealth, and regarding this the verse was revealed: "And know that whatever you obtain as spoils of war, one fifth of it is for Allah and the Messenger." [Surah al-Anfal: 41] This happened after Badr.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17987