Amr bin As reported,

He heard the Messenger of Allah ﷺ say, "When a judge renders a ruling, exercising his judgment and arrives at the correct decision, he receives two rewards. When he renders a ruling, exercising his judgment and errs, he receives one reward."

Azami 6714

Sahih

عن عمرو بن العاص

أنه سمع رسول الله ﷺ يقول: إذا حكم الحاكم فاجتهد ثم أصاب فله أجران، وإذا حكم فاجتهد ثم أخطأ فله أجر.

الأعظمي 6714صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Judgeship
Chapter
Conduct of the judge
Section
Judge errs
Numbering
Jami al-Kamil 6714 (2nd edition)
Azami 6714