It has been mentioned by Abu’ Nu’aim in ‘Hilya’ from Anas Ibn Malik (Allah be pleased with him) he said, that the Messenger of Allah (Allah bless him and give him peace) used to make the following dua, when the month of Rajab came in:
‘Allahuma Barik lana fi Rajaba wa Sha’bana wa ballighna Ramadhan’
It has bee mentioned by Abu’l Fath ibn Abi’l-Fawaris in his ‘Amali’ (dictations and transmissions) and Allama Suyuti has also mentioned in his Jami Saghir from Hasan Basri that the Messenger of Allah (Allah bless him and give him peace) said,
“Rajab is the month of Allah. Shaban is my month. Ramadhan is the month of my ummah (followers).”
From the above hadith, it shows that it is preferable to make dua, to remain in the coming and following months, in order to perform good actions in them, because a true believer increases in his age with goodness. The best of people is the one who lives long and performs good actions.
The pious predecessors used to prefer dying after performing good actions, like the fast of Ramadhan or returning from Haj. And it was said by them, ‘whoever dies in this way, is forgiven.’
There is no doubt that the month of Rajab is the key to the opening of the months of goodness and blessing