Is there anything in the Sunnah that indicates fasting the first three days of Rajab and the middle of Sha'ban?

The Prophet, peace and blessings be upon him, used to fast frequently in Sha'ban because it is a month in which deeds are raised to Allah, and people are heedless of it, coming between Rajab and Ramadan. There is no established proof for singling out the beginning of Sha'ban or its middle for fasting; rather, that is an innovation.