The Prophet ﷺ did not fast in any month of the year more than he fasted in Shaban. He used to fast all of Shaban, and he would say, "Take on of religious deeds what you are able to sustain, for Allah does not tire until you tire."The prayer most beloved to him was the one performed consistently, even if it were small in amount, and whenever he undertook a prayer, he would maintain it regularly.
حدثنا عبد الوهاب قال أخبرنا هشام الدستوائي عن يحيى بن أبي كثير عن أبي سلمة بن عبد الرحمن أن
أن النبي ﷺ لم يكن يصوم من شهر من السنة أكثر من صيامه من شعبان فإنه كان يصوم شعبان كله وكان يقول خذوا من العمل ما تطيقون فإن الله عز وجل لا يمل حتى تملوا فإنه كان أحب الصلاة إليه ما داوم عليها وإن قل وكان إذا صلى صلاة يداوم عليها
Its isnad is sahih. Bukhari narrated it, 4/212, no. 1969, Fath, Abu Dawud, 2/300, no. 2336, Tirmidhi, 3/104, no. 736, and he graded it hasan, Nasai, 4/151, no. 2179, and Ibn Majah, 1/545, no. 1710, all of them in the chapters on fasting.