Masruq (may Allah have mercy on him) said: A scribe wrote on behalf of Sayyiduna Umar (may Allah be pleased with him): This is what Allah has shown the Commander of the Believers, Umar (may Allah be pleased with him). Sayyiduna Umar (may Allah be pleased with him) rebuked him and said: Write: This is the opinion of Umar. If it is correct, it is from Allah, and if it is wrong, it is from Umar.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20348