A MUSLIM DOES NOT HOLD A GRUDGE
A Muslim does not hold a grudge. Grudge is a attribute of people who are not on the right path. Holding a grudge is a attribute of unbelief[1]. They continuously hold a grudge. It is one of the qualities of Shaitan: he has been holding a grudge since Adam Alayhis Salam and he makes those who follow him hold a grudge. Against whom? Against Muslims, those on the path of Allah.
1. Kufr 2. Muhabbat 3. Awliya 4. Sahaba 5. Mumins