'Aishah (May Allah be pleased with her) reported:
The Messenger of Allah (ﷺ) used to observe I'tikaf in the last ten days of Ramadan and say, "Seek Lailat-ul-Qadr (Night of Decree) in the odd nights out of the last ten nights of Ramadan."[Al- Bukhari]. (DE)
App reference (DE): Book 9, Hadith 202 (DE)
Arabic/English book reference (DE): Book 9, Hadith 1192 (DE)