The Messenger of Allah ﷺ said, "You bring your disputes to me, and perhaps some of you are more eloquent in presenting their case than others. I judge in favor of the one whose words I hear. So whoever I rule in favor of, granting him something that belongs to his brother, I am only cutting out for him a piece of the Fire, so let him not take it."
حدثنا يحيى عن هشام قال حدثنى أبي عن زينب بنت أبي سلمة
أن رسول الله ﷺ قال إنكم تختصمون إلي ولعل بعضكم ألحن بحجته من بعض وإنما أقضي له بما يقول فمن قضيت له بشيء من حق أخيه بقوله فإنما أقطع له قطعة من النار فلا يأخذها
Its isnad is sahih. Zaynab bint Abu Salama was the stepdaughter of the Prophet ﷺ. The hadith was narrated by Bukhari 5/388 no. 2680 in "Testimonies," Muslim 3/1337 no. 1713 in "Judgments," and likewise Abu Dawud 3/301 no. 3583, Tirmidhi in "Rulings" 3/615 no. 1339 where he said, hasan sahih. Nasai 8/233 no. 5401 in "Judgment," and Ibn Majah 2/777 no. 2317 in "Rulings."