Amr bin As reported,

Two disputants came to the Messenger of Allah ﷺ with a quarrel between them, and he said to Amr, "Judge between them, Amr."Amr replied, "You are more worthy of that than I am, Messenger of Allah."The Prophet ﷺ said, "Even so."Amr asked, "And if I judge between them, what do I get?"He answered, "If you judge between them and reach the correct ruling, you have ten good deeds, and if you exert your best effort and get it wrong, you have one good deed."In another wording, he said, "If you exert your best effort and reach the correct ruling, you have ten rewards, and if you exert your best effort and get it wrong, you have a single reward."

Ahmad 17825

Daif

حدثنا هاشم قال ثنا الفرج عن ربيعة بن يزيد عن عقبة بن عامر عن النبي ﷺ مثله غير أنه قال فإن اجتهدت فأصبت القضاء فلك عشرة أجور وإن اجتهدت فأخطأت فلك أجر واحد

أحمد 17825ضعيف
Contents
Reference
Commentary
Ayat
Collection
Musnad Ahmad
Book
Amr bin As
Numbering
Darussalam 17825
Ahmad 17825