The Book of Sacrifices
35/1. Chapter:
The time for sacrifice
Sahih Muslim
وَحَدَّثَنَاهُ ابْنُ الْمُثَنَّى، حَدَّثَنِي وَهْبُ بْنُ جَرِيرٍ، ح وَحَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا أَبُو عَامِرٍ الْعَقَدِيُّ، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ . وَلَمْ يَذْكُرِ الشَّكَّ فِي قَوْلِهِ هِيَ خَيْرٌ مِنْ مُسِنَّةٍ .
This hadith has been narrated on the authority of Shu'ba with the same chain of transmitters, but did not mention tht doubt (expressed in his statement) That is (the goat of less than a year) is better than a goat of more than one year.
Reference : Sahih Muslim 1961jIn-book reference : Book 35, Hadith 15USC-MSA web (English) reference : Book 22, Hadith 4832