Ibrahim bin Ishaq Al-Ahmari, from a group, from Ibn Faddal, from Abdullah bin Bukayr, from his father Bukayr bin A'yun, who said: I asked Abu Abdullah عليه السلام: “In which nights should I perform ghusl during the month of Ramadan?” Imam عليه السلام said: "On the nineteenth, the twenty-first, and the twenty-third (of month of Ramadan), and the ghusl should be at the beginning of the night." I said: “What if someone sleeps after performing ghusl?” Imam عليه السلام said: "It is like the ghusl of Friday - if you perform it after Fajr, it suffices you."