It is narrated from Imam Hassan ibn Ali (AS) who said:

I have not lived a day in which I had the hatred of any Muslim in my Heart, or wish any bad or harm for anyone. Swear to God, now that I have woken up in the morning, I have no hatred in my heart of anyone from this Ummah in the west or east of this world [1].

The Grand Ayatollah Javadi Amoli said: Divine men and women pray to God: O’ Allah (SWT), do not allow the hatred of anyone to enter my heart. The hatred is an internal occupation for the human being, and it bothers the human being. It does not allow the person to concentrate on Salaat, nor does it allow a good sleep, or any other task. Of course enmity towards disbelievers and enemies of Islam is OK, because this enmity is not a personal matter, rather it is one of the signs of Tawalli (friendship with those who love God) and Tabarri (disassociation with those who oppose God) [2].

[1] Farhang-e-Sokhanane Imam Hassan (AS), Page 257.

[2] Ethics Lesson, Qom, (13 May 2004).

Source: en.shafaqna.com