I have heard that raising one's hands for du'a after each salat is bid'a. Is this true? I also heard that the Prophet (PBUH) never really raised his hands in Du'a except in Salat Istisqa'a. Are there other instances where the Prophet (PBUH) raised his hands? There is also a Hadith in which the Prophet (PBUH) said that Allah is shy of His servant when he raises his hands in Du'a, and Allah does not like to not answer his prayer when he puts his hands down. I would like to know where this Hadith is and it's authenticity.
Any answer that has no citation or sources will be rejected
It is a Sunnah to raise the hands when supplicating. The Prophet S.A.W said: "Your Lord is Hayyiy (which implies bashfulness) and Kareem (which implies generosity), and is bashful to turn away empty the hands of His Servant when he raises them to Him." [Abu Daawood]. However, without any evidence about rubbing both hands against each other before or after the supplication, this matter cannot be legislated as part of the religion. If this is done occasionally without having the intention of it being an act of worship through which one seeks getting near to Allaah there is no harm in it, Inshaa' Allaah, provided that it does not become a habit.
Allaah knows best.