Explanation

‘Ā'ishah (may Allah be pleased with her) mentioned that they performed Hajj with the Prophet (may Allah's peace and blessings be upon him) on the Farewell Hajj, and after they had finished their rituals, they moved on to the Sacred Mosque to perform the Tawāf of Ifādah. His wife Safiyyah (may Allah be pleased with her) was with them. When it was the night of departure, Safiyyah got her menses, and the Prophet (may Allah's peace and blessings be upon him) desired from her what a husband desires from his wife. ‘Ā'ishah told him that Safiyyah was having her menses. The Prophet (may Allah's peace and blessings be upon him) thought that she had got her menses before she made the Tawāf of Ifādah. Since this Tawāf is a major pillar of Hajj without which Hajj is not complete, thus, she would prevent them from leaving Makkah until she attained purity from her menses and made Tawāf. So, he, may Allah's peace and blessings be upon him said: "‘Aqra Halqa!", which is a famous statement pronounced without intending its true meaning. The Prophet (may Allah's peace and blessings be upon him) then asked whether she was going to detain them until she attained purity from her menses and made her Tawāf for her Hajj. They told him that she had already performed it before she got her menses. So, the Prophet (may Allah's peace and blessings be upon him) said that she could depart with them, since nothing was left for her to do except the Farewell Tawāf, which she had a concession to leave off.