Authenticity of the dua for Rajab and Shabaan
Q: I would like to know whether reciting the following famous Dua is Sunnah/Permissible/Bidah:
اللَّهُمَّ بَارِكْ لَنَا فِي رَجَبٍ وَشَعْبَانَ، وَبَلِّغْنَا شَهْرَ رَمَضَانَ
Is there a strong command or a sign of permission from Rasulullah Sallallahu Alaihi Wa Sallam regarding the recitation of this Dua in the months of Rajab and Shabaan?