Ibn 'Abbas (RAA) narrated that the Messenger of Allah (ﷺ) said:
"Don't dispute with your brother; don't make jokes with him; and don't make him a promise which you would break." Related by At-Tirmidhi with a weak chain of narrators. (JA)
English reference (JA): Book 16, Hadith 1541 (JA)
Arabic reference (JA): Book 16, Hadith 1498 (JA)