It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) used to observe i'tikaf during the last ten days of Ramadan. Then one year he could not observe i'tikaf, so the following year he observed i'tikaf for twenty days.

Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) used to observe i'tikaf during the last ten days of Ramadan. Then, one year he traveled and could not observe i'tikaf, so the following year he observed i'tikaf for twenty nights.

Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) used to observe i'tikaf during the last ten days of Ramadan. One year he was unable to perform i'tikaf, so when the next year came, he (peace and blessings be upon him) observed i'tikaf for twenty days.