Musnad Ahmad 1153:601

Qutaybah narrated to us, he said: Layth ibn Sa'd narrated to us, from Khalid ibn Yazid, from Sa'id ibn Abi Hilal, from Ishaq ibn 'Umar, from 'Aishah, that she said: "The Messenger of Allah (peace and blessings of Allah be upon him) did not pray the prayer at its other time twice until Allah, the Mighty and Majestic, took his soul."