Do not curse one another, invoking the curse of Allah or His wrath or the fire of Hell
Good hadithعن سمرة بن جندب رضي الله عنه مرفوعاً: «لا تَلاعَنُوا بلعنة الله، ولا بغضبه، ولا بالنار»
Samurah ibn Jundub (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Do not curse one another, invoking the curse of Allah or His wrath or the fire of Hell."
Explanation
This noble Hadīth prohibits the believers from supplicating against one another with certain types of supplication, such as invoking the curse and wrath of Allah, or Hellfire. This is because of the seriousness and gravity of these supplications in the sight of Allah.
Source · Narrated by At-Termedhy - Narrated by Abu Daoud - Narrated by Ahmad
From the Hadith Encyclopedia (hadeethenc.com).