(609) بَابُ قِمَارُ الدِّيكِ
Rabi'a ibn 'Abdullah ibn al-Hadir ibn 'Abdullah reported tht twomen wagered two cocks in the time of 'Umar. 'Umar ordered that the cockbe killed and a man of the Ansar said to him, "Will you kill a somethingwhich glorifies Allah?" So 'Umar left it.
Reference: Al-Adab Al-Mufrad 1261
In-book reference: Book 54, Hadith 3
English translation: Book 54, Hadith 1261