Did you observe fast in the middle of this month. i. e. Sha'ban? He said: No. Thereupon he said to him: When it is the end of Ramadan, then observe fast for one day or two (Shu'ba had some doubt about it) but he said: I think that he has said: two days. (Using translation from Muslim 1161d)

أَنَّ النَّبِيَّ ﷺ قَالَ لِرَجُلٍ هَلْ صُمْتَ مِنْ سُرَرِ هَذَا الشَّهْرِ شَيْئًا؟ يَعْنِي شَعْبَانَ فَقَالَ لَا فَقَالَ لَهُ إِذَا أَفْطَرْتَ رَمَضَانَ فَصُمْ يَوْمًا أَوْ يَوْمَيْنِ شُعْبَةُ الَّذِي شَكَّ فِيهِ قَالَ وَأَظُنُّهُ قَالَ يَوْمَيْنِ