Musannaf Ibn Abi Shayba 13:486

Abu Bakr narrated to us, he said: 'Abdah ibn Sulayman narrated to us, from Sa'id, from Qatadah, from Sa'id ibn al-Musayyib, who said: 'Umar was asked about a sheep for two sheep until the time of *al-haya'*, meaning fertility (abundance of vegetation), and he disliked that.