Imam Ali (AS) narrated from the Prophet of Islam (PBUH) who said:

If a person protects his brother’s (brother in religion) dignity, heaven becomes Wajib for him [1]. The main point of this narration is Muslims dignity which is very important and must be protected at all the times. It must be noted that any word or act which may harm the dignity of Muslims is against the main point of this narration and must be avoided.

[1] Navader-e-Rawandi, Page 101.

Source: en.shafaqna.com