كتاب الصيام
5  
Fasting
Bulugh al-Maram 691
Abu Hurairah (RAA) narrated that The Messenger of Allah (ﷺ) said:
"When it is the middle of Sha'ban do not fast (until it is Ramadan).” Related by the five Imams, but Imam Ahmad declared it to be a weak narration.
وَعَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- أَنَّ رَسُولَ اَللَّهِ ‏- صلى الله عليه وسلم ‏-قَالَ: { إِذَا اِنْتَصَفَ شَعْبَانَ فَلَا تَصُومُوا } رَوَاهُ اَلْخَمْسَةُ, وَاسْتَنْكَرَهُ أَحْمَدُ 1‏ .‏
Reference : Bulugh al-Maram 691
In-book reference : Book 5, Hadith 691
English translation : Book 5, Hadith 711
Hadith Text
Reference