Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said to him or to another person: "Did you fast at the end of Sha'ban?" He replied: "No." The Prophet Muhammad (peace and blessings be upon him) said: "When you do not fast, then keep fasts for two days." (Imam Ibn Hibban, may Allah have mercy on him, says:): The statement of the Prophet Muhammad (peace and blessings be upon him), "Did you fast on the last days of this month?"—in this, a question is asked about a certain action in literal words, but what is meant is to negate the permissibility of performing that action about which the question was asked, i.e., if someone has committed that action, it is tantamount to its rejection. This is similar to the statement of the Prophet Muhammad (peace and blessings be upon him) to Sayyidah Aisha (may Allah be pleased with her): "Are you making the wall a barrier?"—so here, by using interrogative words, what is meant is to reject it. In this way, the Prophet Muhammad (peace and blessings be upon him) ordered that person to keep two fasts in Shawwal, and by this, he meant to compensate. The reason for this is: when the month is of 29 days, the moon remains hidden for two days. At the time when the Prophet Muhammad (peace and blessings be upon him) said this, there was a possibility that Sha'ban could be of 30 days on that occasion. For this reason, the Prophet Muhammad (peace and blessings be upon him) ordered to keep two fasts in Shawwal.