كتاب الأضاحى
35  
The Book of Sacrifices
(1)
Chapter: The time for sacrifice
(1)
باب وَقْتِهَا ‏‏
Sahih Muslim 1961 j

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.

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 ‏.‏
Reference : Sahih Muslim 1961j
In-book reference : Book 35, Hadith 15
USC-MSA web (English) reference : Book 22, Hadith 4832
  (deprecated numbering scheme)