Musnad Ahmad 1153:911

'Affan narrated to us, Abu 'Awanah narrated to us, Isma'il al-Suddi narrated to us, from 'Abdullah al-Bahiy, from 'A'ishah, she said: "I would not make up what was upon me of Ramadan, except in Sha'ban, until the Messenger of Allah, peace and blessings of Allah be upon him, passed away."