Nafi' said that Ibn Umar (may Allah be pleased with them both) had a friend from the people of al-Sham who used to write letters to him. Ibn Umar (may Allah be pleased with them both) said: "It has reached me that you have spoken about divine decree; do not write to me in future. I heard the Messenger of Allah (peace and blessings be upon him); he (peace and blessings be upon him) said: 'There will be people in my ummah who will deny divine decree.'"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20881