Musnad Ahmad 1153:1444

'Abd al-Rahman narrated to us, he said: Za'idah narrated to us, from al-Suddi, from 'Abd Allah al-Bahiy, from 'A'ishah, she said: "I would not make up what remained upon me of Ramadan during the entire lifetime of the Messenger of Allah, peace and blessings of Allah be upon him, except in Sha'ban."