Sayyidah Aishah (may Allah be pleased with her) said that he (peace and blessings be upon him) would sleep in the first part of the night and stay awake in the last part of the night. Then, if he (peace and blessings be upon him) had a need with his wife, he would fulfil it, and then sleep before touching water. When the first call (adhan) was made, he (peace and blessings be upon him) would spring up at once. By Allah, Aishah (may Allah be pleased with her) did not say that he (peace and blessings be upon him) stood up and took water, and by Allah, Aishah (may Allah be pleased with her) did not say that he (peace and blessings be upon him) performed the ritual bath, but I know what Aishah (may Allah be pleased with her) meant. If he (peace and blessings be upon him) had no need, he would perform an ablution like the ablution for prayer, then offer two rak'ahs.
The huffaz (hadith masters) criticised the wording "before touching water" and considered it to have been taken from someone other than al-Aswad; Abu Ishaq would sometimes commit tadlis (concealing a link in the chain), so they regarded it as one of his tadlis, and they cited as evidence the narration of Ibrahim al-Nakha'i and Abd al-Rahman bin al-Aswad from al-Aswad, which differs from the narration of Abu Ishaq.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 975