Musannaf Ibn Abi Shayba 1:676

'Utham (Ghannam) ibn 'Ali narrated to us, from Hisham, from his father, from 'Aisha, regarding a man who is afflicted by janaba (major ritual impurity) at night and wishes to sleep: She said: "He performs wudu (ablution) or he performs tayammum (dry ablution)."