Sahih Muslim 1089
Sahih Muslim · Book 13: The Book of Fasting · The meaning of the Prophet's words: "The two months of 'Id cannot both be incomplete"
'Abd ar-Rahman b. Abu Bakra reported on the authority of Abu Bakra that the Messenger of Allah (ﷺ) had said:
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، قَالَ حَدَّثَنَا مُعْتَمِرُ بْنُ سُلَيْمَانَ ، عَنْ إِسْحَاقَ بْنِ سُوَيْدٍ ، وَخَالِدٍ عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي بَكْرَةَ ، عَنْ أَبِي بَكْرَةَ ، أَنَّ نَبِيَّ اللَّهِ صلى الله عليه وسلم قَالَ " شَهْرَا عِيدٍ لاَ يَنْقُصَانِ " . فِي حَدِيثِ خَالِدٍ " شَهْرَا عِيدٍ رَمَضَانُ وَذُو الْحِجَّةِ " .
The months of 'Id are not incomplete. And in the hadith narrated by Khalid (the words are):" The months, of 'Id are Ramadan and Dhu'l-Hijja."