Sha’aban is a month of high excellence and is dedicated to the Leader of the Prophets (PBUH). He used to keep fasts during this month and join it with the month of Ramadhan.
He used to say, “Sha’aban is a month dedicated to me. Whoever keeps one fast during my month will definitely go to heaven”. It has been reported from Imam Ja’far Sadiq (a.s) that on the commencement of this month, Imam Zainul Abideen (a.s) would gather his companions and address them, “O my companions, do you know which month this is? It is the month of Sha’aban about which the Holy Messenger (PBUH) used to say that it is dedicated to him. So keep fasts during this month in the love of your Holy Prophet (PBUH) and to attain closeness to your Creator. By Allah in whose hands is my soul, I have heard from my father, Hussein ibn Ali (a.s), that he had heard from Commander of Faithful (a.s), that whoever keeps fast during Sha’aban in the love of the Holy Prophet (PBUH) and to attain closeness to Allah will become a friend to Allah and on the Day of Judgment will be close to Allah by His grace and Paradise will be assured to him.”
Sheikh Tusi has reported from Safwane Jammal that Imam Ja’far Sadiq (a.s) asked him to encourage his neighbors and friends to fast in the month of Sha’aban. He asked the Imam if there was any special significance for it, and he replied that when the month commenced, the Holy Messenger (PBUH) would command his announcer to proclaim in Medina that the Holy Messenger (PBUH) wished them to be aware that Sha’aban was a month dedicated to him and Allah bestows mercy on whosoever associates with him in this month by fasting. Imam Ja’far Sadiq (as) proceeded to report from Commander of Faithful (as) that since hearing the announcement, he never missed any fast during the month of Sha’aban and, Allah willing, hoped not to miss any during the remainder of his life. He added that fasting in the months of Sha’aban and Ramadhan is a means of repentance and pardon from Allah.
Keeping fast on Thursdays of the month also carried great significance. It has been reported that the heavens are decorated each Thursday in the month of Sha’aban and the angles pray to Allah to forgive all those who fast on that day and their prayers are accepted.
It is stated in the reports of the narrations of the Holy prophet (PBUH) that whoever fasts on Mondays and Thursdays of this month, Allah will fulfill twenty of his worldly wishes and twenty of his wishes of the Hereafter. It is recommended to give alms in this month even if it is as small as a half date. Almsgiving in this month brings about rescue from Hellfire. In this respect, it has been narrated that when Imam al-Sadiq (a.s) was asked about the merits of observing fasting in Rajab, he answered, “Why do you not ask about the merits of observing fasting in Sha’aban.” “What is then the reward of him who observes fasting on one day in Sha’aban, Son of Allah’s Messenger?” asked the narrator. The Imam (a.s) answered, “The reward will be Paradise. I swear it by Allah.” The narrator then asked again, “What are the best deeds that should be done in Sha’aban.” The Imam (a.s) answered, “Almsgiving and seeking forgiveness are the best deeds in Sha’aban. Verily, if anyone of you gives alms in Sha’aban, Almighty Allah will breed that alms in the very same way as you breed your small camels. Hence, these alms will be as huge as Mount Uhud on the Resurrection Day.”
* Source: duas.org