Musnad Ahmad 1012:42

Musa ibn Dawud narrated to us, Ibn Lahi'ah narrated to us, from Yazid ibn Abi Habib, that al-Walid ibn Ubadah ibn al-Samit said: My father, may Allah have mercy on him, advised me and said: "O my son, I advise you to believe in the decree (al-qadar), its good and its evil; for if you do not believe [in it], Allah will cause you to enter the Fire." He said: And I heard the Prophet, peace and blessings of Allah be upon him, saying: "The first thing Allah created was the Pen, then He said to it: 'Write.' It said: 'What shall I write?' He said: 'The decree.' So it wrote what has been and what will be until the Hour is established."