Situations when jesting become a serious offense:

بسم الله والحمد لله والصلاة والسلام على رسول الله ، وبعد

1) Mocking or making fun of any aspect of the Deen is Kufr:

﴿وَلَئِن سَأَلْتَهُمْ لَيَقُولُنَّ إِنَّمَا كُنَّا نَخُوضُ وَنَلْعَبُ ۚ قُلْ أَبِاللَّـهِ وَآيَاتِهِ وَرَسُولِهِ كُنتُمْ تَسْتَهْزِئُونَ * لَا تَعْتَذِرُوا قَدْ كَفَرْتُم بَعْدَ إِيمَانِكُمْ﴾

❝{If you ask them (about this), they declare: "We were only talking idly and joking." Say: "Was it at Allaah, and His Aayaat (proofs, evidences, verses, etc.) and His Messenger that you were mocking?” Make no excuse; you have disbelieved after you had believed.}❞ [Surah al-Tawbah (9): 65-66]

Making fun of any aspect of the Deen or the Sunnah of the Prophet صلى الله عليه وسلم like making fun of the beard or about maintaining the lower garments above the ankles etc.

2) It is counted as a divorce even if the person uttering it was only jesting:

It was narrated from Abu Hurairah that the Messenger of Allaah صلى الله عليه وسلم said: ❝There are three matters in which seriousness is serious and joking is serious: marriage, divorce and taking back (one's wife after divorce which is not final).❞ [Sunan Ibn Maajah (2039), Sunan Abu Dawood (2194) and Sunan al-Tirmidhee (1184) and graded as “Hasan” by Shaikh al-Albaanee]

3) Lying while joking:

Mu’aawiyah ibn Haydah رضي الله عنه said: I heard the Prophet صلى الله عليه وسلم say: ❝Woe to the one who talks to make the people laugh and tells lies, woe to him, woe to him.❞ [Sunan al-Tirmidhee (2315) and Sunan Abu Dawood (4990) and graded as “Hasan” by Shaikh al-Albaanee].

4) Practical jokes and pranks:

Narrated `Abdullaah ibn as-Saa’ib ibn Yazeed رضي الله عنه: The Messenger of Allaah صلى الله عليه وسلم said: ❝None of you should take the property of his brother in amusement (i.e. jest), nor in earnest. If anyone takes the staff of his brother, he should return it.❞ [Sunan Abu Dawood (5003) and graded as “Hasan” by Shaikh al-Albaanee]


5) Scaring people:

Narrated `Abdul Rahmaan ibn Abu Layla: The Companions of the Prophet صلى الله عليه وسلم told us that they were travelling with the Prophet صلى الله عليه وسلم. A man among them went to sleep, and another one of them went to the rope which he had with him. He took it, by which he (the one who was sleeping) got frightened. The Prophet صلى الله عليه وسلم said: ❝It is not lawful for a Muslim that he frightens a Muslim.❞ [Sunan Abu Dawood (5004) and graded as “Saheeh” by Shaikh al-Albaanee]