Sunan an-Nasa'i, Book 22, Hadith 268 (In-Book) ⓘ
Usamah bin Zaid said: "I said: 'O Messenger of Allah, I do not see you fasting any month as much as Shaban.' He said: 'That is a month to which people do not pay much attention, between Rajab and Ramadan. It is a month in which the deeds are taken up to the Lord of the worlds, and I like that my deeds be taken up when I am fasting."'
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، عَنْ عَبْدِ الرَّحْمَنِ، قَالَ حَدَّثَنَا ثَابِتُ بْنُ قَيْسٍ أَبُو الْغُصْنِ، - شَيْخٌ مِنْ أَهْلِ الْمَدِينَةِ - قَالَ حَدَّثَنِي أَبُو سَعِيدٍ الْمَقْبُرِيُّ، قَالَ حَدَّثَنِي أُسَامَةُ بْنُ زَيْدٍ، قَالَ قُلْتُ يَا رَسُولَ اللَّهِ لَمْ أَرَكَ تَصُومُ شَهْرًا مِنَ الشُّهُورِ مَا تَصُومُ مِنْ شَعْبَانَ . قَالَ " ذَلِكَ شَهْرٌ يَغْفُلُ النَّاسُ عَنْهُ بَيْنَ رَجَبٍ وَرَمَضَانَ وَهُوَ شَهْرٌ تُرْفَعُ فِيهِ الأَعْمَالُ إِلَى رَبِّ الْعَالَمِينَ فَأُحِبُّ أَنْ يُرْفَعَ عَمَلِي وَأَنَا صَائِمٌ " .
also referenced under: Hadith 2357 (Reference) & Volume 3, Book 22, Hadith 2359 (DarusSalam)