Musnad Abu Ya'la al-Mawsili 149:42

Abu Talib Abd al-Jabbar ibn Asim narrated to us, Ubayd Allah ibn Amr narrated to me, from Ayyub, from Abu Qilabah, from Abdullah ibn Yazid, from Aisha, from the Prophet (peace and blessings of Allah be upon him), who said: "No one among the Muslims dies, and a group of Muslims prays over him, reaching the number of one hundred, and they intercede for him, but that they are granted intercession for him."