Zayd bin Aslam narrates with his chain that then "he (peace and blessings be upon him) took a handful and washed his right foot with it, then took a handful and washed his left foot with it."
(b) All these narrations agree on the washing of the feet. In the hadith of al-Darawardi there is the possibility that he (peace and blessings be upon him) washed his feet while they were in the sandals.
(c) Hisham bin Sa'd is not very strong; his contradiction of the reliable (thiqah) narrators is not acceptable, for they are a whole group and he is alone.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 346