The Prophet ﷺ heard some people disputing with one another, so he said, "Those who came before you were destroyed only because of this. They struck parts of the Book of Allah against other parts, when the Book of Allah was revealed with its parts confirming one another. So do not deny one part of it by another. Whatever you know of it, speak of it, and whatever you do not know, leave it to one who knows."
سمع النبي ﷺ قوما يتدارؤون فقال: إنما هلك من كان قبلكم بهذا، ضربوا كتاب الله بعضه ببعض، وإنما نزل كتاب الله يصدق بعضه بعضا، فلا تكذبوا بعضه ببعض، فما علمتم منه فقولوا، وما جهلتم فكلوه إلى عالمه.
Imam Ahmad narrated it (6741) from Abdul-Razzaq, and it is also in his Musannaf (20367), where he said, Mamar informed us, from Zuhri, from Amr bin Shuayb, from his father, from his grandfather, and he mentioned the hadith.Through this same route, it was also narrated by Bukhari in Khalq Afal Abbad (218), by Baghawi in Sharh al-Sunnah (121), and by Bayhaqi in Madkhal (789).Its isnad is hasan, because of the discussion concerning Amr bin Shuayb, for his hadith is hasan.See for more, "Qadr."