Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah (ﷺ) said, "People's deeds are presented before Allah on Mondays and Thursdays, and then every slave (of Allah) is granted forgiveness (of minor sins) if he does not associate anything with Allah in worship. But the person in whose heart there is rancour against his brother, will not be pardoned. With regard to them, it is said twice: 'Hold these two until they are reconciled'."[Muslim].
App reference: Book 18, Hadith 83
Arabic/English book reference: Book 18, Hadith 1593