It is narrated in the Musannaf of Ibn Abi Shaybah (30364) and in his Kitab al-Iman (106) that Abu Darda (rn) made this following Du'a:
'Ya Allah, I ask You for permanent faith (Iman), beneficial knowledge, and valuable guidance' Mu'awiyah said: '[From this Du'a we understand that] Iman is not always perpetual, there is knowledge that is not beneficial and guidance that is not valubale.'
I would like to know the authenticity for this supplication since I can not find any classification for it?