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’ (O Allah Bless us in Rajab and Sha’ban and Bring us 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.
Abu Bakr Warraq (May Allah be pleased with him) said,
‘Rajab is a month of cultivation, Shaban is month of irrigating the fields, and the month of Ramadhan is a month of reaping and harvesting.’
The summary is, that the month of Rajab is a sacred month and the first, virtuous and noble of them all. So it is appropriate to celebrate it ENTIRELY and to give attention to it by performing good acts, and refraining oneself from sins and offensive things, because it is the month of Allah.
It has been mentioned that Allah said,‘Fasting is for me and I will recompense for it.’
Fasting in the month of Rajab prevents one from sins, let alone refraining one from killing and having enmity towards the enemy (which this month was made sacred for), like it was practised by the people in the ignorant (jahili) period.
(Imam Abdul’Gani al-Nablusi, Fadha’il al-Shu’hur wa’l-Ayyam (Virtues of Months and Days) pg 27, 32)Sunnipath.com