Ayesha reported,

The Messenger of Allah ﷺ used to fast so often that we would say he would never break his fast, and he would go without fasting so often that we would say he would never fast. I never saw the Messenger of Allah ﷺ complete a full month of fasting except in Ramadan, and I never saw him fast more in any month than he did in Shaban.

Bukhari 1969

Sahih

حدثنا عبد الله بن يوسف أخبرنا مالك عن أبي النضر عن أبي سلمة

عن عائشة رضي الله عنها قالت

كان رسول الله ﷺ يصوم حتى نقول لا يفطر ويفطر حتى نقول لا يصوم فما رأيت رسول الله ﷺ استكمل صيام شهر إلا رمضان وما رأيته أكثر صياما منه في شعبان

البخاري 1969صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Fasting
Chapter
Fasting in Shaban
Numbering
Darussalam 1969
Bukhari 1969