The hadith is found in Sunan al-Bayhaqi al-Kabir 4: 277, and Musannaf Ibn Abi Shaybah 2: 289, and Musannaf Abdul Razzaq 4: 274, and in Fayd al-Qadir 4: 231: from the hadith of Awn ibn Amarah from Hamid from Anas, al-Bayhaqi said: and Awn is weak, and from Ja'far ibn al-Zubair from al-Qasim from Abu Umamah, al-Dhahabi said: and Ja'far is abandoned. It was also narrated from Ibrahim ibn Muzahim from Sari' ibn Nabhan from Abu Dharr, al-Dhahabi said: and Ibrahim and Sari' are unknown. Al-Zailai said in al-Tayyin 1: 238-239: "It is not authentic; because in its chain is Ja'far ibn al-Zubair who is abandoned, and even if it were authentic, the intended meaning is to clarify the time to start it; because it is not permissible after noon, so its meaning is that whoever wants to fast voluntarily, he has the option until noon, if he wishes he may start it and if he wishes he may not start it, as it is said: whoever enters upon the Sultan should prepare himself: meaning whoever wants to enter upon him."