Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: Sayyiduna Umar (may Allah be pleased with him) stated that when the Prophet Muhammad (peace and blessings be upon him) returned from Hunayn, Sayyiduna Umar (may Allah be pleased with him) asked the Prophet (peace and blessings be upon him) about the vow he had made in the days of ignorance to perform i'tikaf (seclusion in the mosque) for one day. The Prophet (peace and blessings be upon him) ordered him to fulfill it. Sayyiduna Umar (may Allah be pleased with him) narrates: He went ahead of the Prophet (peace and blessings be upon him). Sayyiduna Umar (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) had sent a slave girl with me who was among the captives of Hunayn. Sayyiduna Umar (may Allah be pleased with him) narrates: I lodged her in the houses of the villagers until, when I camped, some captives of Hunayn came before me who had run out and were saying: The Messenger of Allah has set us free. So Sayyiduna Umar (may Allah be pleased with him) said to Sayyiduna Abdullah (may Allah be pleased with him): Go and set that slave girl free. Sayyiduna Abdullah (may Allah be pleased with him) narrates: So I went and I set her free.

(Imam Ibn Hibban, may Allah have mercy on him, says:) In the wording of the narration, Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) has clarified that Sayyiduna Umar (may Allah be pleased with him) had made a vow to perform i'tikaf for one night, and this is mentioned only in this narration, because the wording of this narration is: Sayyiduna Umar (may Allah be pleased with him) had made a vow to perform i'tikaf for one day. So if these words are authentically established, then it is possible that by "day" here it is meant: to perform i'tikaf along with the night of that day, and where the word "night" is used, it means that its day will be included. In this way, there will remain no contradiction between the two narrations.