Yahya bin Yamar reported,

The first person to speak about qadar in Basra was Mabad al-Juhani. So I and Humayd bin Abdul-Rahman al-Himyari set out for Hajj or Umrah, and we said to one another, "If only we could meet one of the companions of the Messenger of Allah ﷺ and ask him about what these people are saying regarding qadar."By good fortune, Abdullah bin Umar was granted to us as he was entering the mosque. My companion and I flanked him, one on his right and the other on his left. I thought my companion would leave the talking to me, so I said, "Abu Abdul-Rahman, certain people have appeared among us who recite the Quran and pursue knowledge," and I described their state, "claiming that there is no qadar and that matters occur without prior decree."He replied, "When you meet those people, tell them that I am free of them and they are free of me. By the One whom Abdullah bin Umar swears by, if one of them had gold equal to Mount Uhud and spent it, Allah would not accept it from him until he believes in qadar."Then he said, "My father Umar bin Khattab told me, 'While we were sitting with the Messenger of Allah ﷺ one day, a man with strikingly white clothing came upon us...'" and he mentioned the hadith in full, which includes, "...and that you believe in qadar, both its good and its evil."

Azami 995

Sahih

عن يحيى بن يعمر قال

كان أول من تكلم في القدر بالبصرة معبد الجهني، فانطلقت أنا وحميد بن عبد الرحمن الحميري حاجين أو معتمرين، فقلنا: لو لقينا أحدا من أصحاب رسول الله ﷺ فسألناه عما يقول هؤلاء في القدر، فوفق لنا عبد الله بن عمر داخلا المسجد، فاكتنفته أنا وصاحبي أحدنا عن يمينه والآخر عن شماله، فظننت أن صاحبي سيكل الكلام إلي. فقلت: أبا عبد الرحمن، إنه قد ظهر قبلنا ناس يقرؤون القرآن ويتفقرون العلم (أي يطلبونه)، وذكر من شأنهم يزعمون أن لا قدر، والأمر أنف (أي مستأتف، لم يسبق به قدر، ولا علم من الله تعالى، وإنما يعلمه بعد وقوعه)؟ قال: إذا لقيت هؤلاء فأخبرهم أني بريء منهم، وأنهم براء مني. والذي يحلف به عبد الله بن عمر لو أن لأحدهم مثل أحد ذهبا فأنفقه ما قبل الله منه، حتى يؤمن بالقدر، ثم قال: حدثني أبي عمر بن الخطاب قال: بينما نحن عند رسول الله ﷺ ذات يوم، إذ طلع علينا رجل شديد بياض الثياب. فذكر الحديث بطوله، وفيه: أن تؤمن بالقدر خيره وشره.

الأعظمي 995صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Faith
Chapter
Belief in the divine decree and predestination
Section
First to speak about divine decree
Numbering
Jami al-Kamil 995 (2nd edition)
Azami 995