What is the authenticity of the hadith: “The Messenger of Allah (peace and blessings be upon him) did not break his fast on the white days”?

Question:
From Ibn Abbas (may Allah be pleased with them both): The Messenger of Allah (peace and blessings be upon him) did not break his fast on the white days, neither while traveling nor while resident. Is this established from the Messenger of Allah?

Answer:
We do not know of its authenticity. Rather, it is established from him that he would sometimes fast consecutively until it was said, “He does not break his fast,” and he would sometimes break his fast consecutively until it was said, “He does not fast.” This is established from the hadith of Ibn Abbas, Aisha, and others from him (peace and blessings be upon him). So he might fast them, and he might not fast them, (peace and blessings be upon him).
However, it is a recommended practice to fast them. It is a recommended practice to fast them. He might fast them (peace and blessings be upon him) at some times, and he might be occupied with other matters and not fast them. He would fast consecutively at other times, just as he would fast on Mondays and Thursdays. He might be occupied with other matters and not fast them, (peace and blessings be upon him).