Abu Dawud said "Yahya bin Sa'id used to object to this tradition for this is not from his early traditions because his memory was spoiled at the age of forty five. He narrated this tradition in the last days of his age."
Abu Dawud said " It is said that Waki " recived this tradition from him when his memory was spoiled."
In-book : Book 15, Hadith 219
English translation : Book 14, Hadith 2689