Amr bin Shu'ayb (may Allah have mercy on him) narrates from his father Shu'ayb (may Allah have mercy on him), from his grandfather Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both), that he said: The Messenger of Allah (peace and blessings be upon him) heard some people disputing with one another, and he said: "Those before you were destroyed only because of this: they set one part of the Book of Allah against another. Yet the Book of Allah was revealed so that one part of it confirms another; so do not deny one part of it by means of another. Whatever of it you know, say it, and whatever of it you do not know, leave it to the one who knows it."
No one narrated this hadith except Ma'mar (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 2995
Hadith Takhrij«أخرجه مسلم فى «صحيحه» برقم: 2666، والنسائي فى «السنن الكبرى» برقم: 8041، 11830، وابن ماجه فى «سننه» برقم: 85، وسعيد بن منصور فى «سننه» برقم: 36، وأحمد فى «مسنده» برقم: 6779، 6817، 6856، 6919، 6964، 6965، وأبو يعلى فى «مسنده» برقم: 3121، والبزار فى «مسنده» برقم: 2489، 2490، وابن حجر فى «المطالب العالية» برقم: 2947، وعبد الرزاق فى «مصنفه» برقم: 20367، والطبراني فى «الكبير» برقم: 14177، 14519، والطبراني فى «الأوسط» برقم: 515، 1308، 7052»