Musannaf Ibn Abi Shayba 36:504

Hatim narrated to us, from Ja'far, from his father, who said: When the Prophet, peace and blessings of Allah be upon him, became heavy [ill], he said: "Where will I be tomorrow?" They said: "At the place of so-and-so." He said: "Where will I be the day after tomorrow?" They said: "At the place of so-and-so." His wives realized that he only wanted 'Aisha, so they said: "O Messenger of Allah, we have gifted our days to our sister 'Aisha."