Al-Matalib al-'Aliyah 1030 — The concession to delay making up Ramadan

Al-Aswad bin Qays (may Allah have mercy on him) narrates from his father that a man asked the Commander of the Believers, Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), about making up the missed fasts of Ramadan during the first ten days of Dhu al-Hijjah. The narrator said: I could not learn the full exchange that took place between the two of them, but Sayyiduna Umar (may Allah be pleased with him) ordered him to make up Ramadan during the first ten days of Dhu al-Hijjah. And al-Aswad's father said (to his son): Do not say that your father heard this directly from Sayyiduna Umar (may Allah be pleased with him) in person.
This report establishes that it is permissible to make up Ramadan during the blessed days of Dhu al-Hijjah, so that the blessings of these days may be obtained and there is no delay in doing good.