On the authority of Anas (may Allah be pleased with him): The Messenger of Allah (may Allah bless him and grant him peace), used to say the following when the month of Rajab began.
اَللّهُمَّ بَارِكْ لَنَا فِى رَجَبَ وَ شَعْبَانَ وَ بَلِّغْنَا رَمَضَان
“Oh Allah! Bless us in Rajab and Sha`ban, and bring us, oh Allah, to Ramadan.”
[Narrated by Tabarani and Ahmad]