Abu Dawud
Fasting
Book Number: 007 / Hadith Number: 2362
Narated By Shaddad ibn Aws : The tradition mentioned above (No. 2361) has also been transmitted by Shaddad ibn Aws through a different chain of narrators.
This version adds: While Shaddad ibn Aws was walking along with the Prophet (pbuh)....The narrator then transmitted the rest of the tradition to the same effect.