It wasnarrated that 'Aishah said:
"When the Prophet (ﷺ) wanted tostart I'tikaf, he would pray the Subh, then he would enter theplacewhere he wanted to observe I'tikaf. He wanted to spend thelast tendays of Ramadan in I'tikaf, so he ordered that a tent beset up forhim." Then 'Aishah ordered that a tent be set up forher, and Hafashordered that a tent be set up for her. When Zainabsaw their twotents, she also ordered that a tent be set up for her.When theMessenger of Allah (ﷺ) saw that, he said: "It isrighteousness thatyou seek?" Then he did not observe I'tikafduring Ramadan, and heobserved I'tikaf during ten days of Shawwal.
English reference: Vol. 1, Book 7, Hadith 1771
Arabic reference: Book 7, Hadith 1843