The Prophet (ﷺ) never fasted in any month more than in the month of Sha'ban. He used to say, "Do those deeds which you can do easily, as Allah will not get tired (of giving rewards) till you get bored and tired (of performing religious deeds)." The most beloved prayer to the Prophet (ﷺ) was the one that was done regularly (throughout the life) even if it were little. And whenever the Prophet (ﷺ) offered a prayer he used to offer it regularly .
Sahih al-Bukhari Book 30, Hadith 77
← Previous Hadith Allah's Messenger (ﷺ) used to fast till one would say that he would never stop fasting, and he would abandon fasting till one would say that he would never fast. I never saw Allah's Messenger (ﷺ) fasting for a whole month except the month of Ramadan, and did not see him fasting in any month more than in the month of Sha'ban.

Sahih al-Bukhari Book 30, Hadith 76 Next Hadith → The Prophet (ﷺ) never fasted a full month except the month of Ramadan, and he used to fast till one could say, "By Allah, he will never stop fasting," and he would abandon fasting till one would say, "By Allah, he will never fast."

Sahih al-Bukhari Book 30, Hadith 78