Is it Sunnah to raise the hands before standing for the third Raka'ah (while sitting), and Bid'ah (innovation) to do so after standing for it?

Raising the hands after rising from the sitting position following the two rak'ahs is recommended by meticulous scholars, and it is one of the two narrations from Ahmad, and the view of a group of his companions, Al-Shafi'i, and others. This has been established from the Prophet, peace and blessings be upon him, in the Sahih and Sunan collections. In Al-Bukhari, Sunan Abi Dawud, and Al-Nasa'i, it is narrated from Nafi' that Ibn 'Umar used to do that and attributed it to the Prophet, peace and blessings be upon him. And from Ali ibn Abi Talib that the Prophet, peace and blessings be upon him, used to do that.