1 – It not should not involve any element of making fun of the Faith and its signs:
That is one of the things that nullify a person’s Islam. Allaah says (interpretation of the meaning): “If you ask them (about this), they declare: ‘We were only talking idly and joking.’ Say: ‘Was it at Allaah, and His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) and His Messenger that you were mocking?’ Make no excuse; you disbelieved after you had believed” [al-Tawbah 9:65-66] for: “Making fun of Allaah, His Signs and His Messenger is (disbelief) and the one who does that disbelieves thereby after he had believed.”
The same applies to making fun of some Sunnahs, an action which is widespread, such as making fun of the beard and the hijaab, or of shortening one’s garment, etc.
2 – The jokes should only be truthful:
The Prophet (peace and blessings of Allaah be upon him) said: “Woe to the one who tells lies to make people laugh, woe to him.” (Narrated by Abu Dawood). The Prophet (peace and blessings of Allaah be upon him) said, warning against this kind of behavior which some jokers are accustomed to: “A man may say something to make his companions laugh, and he will fall into Hell as far as the Pleiades because of it.” (Narrated by Ahmad).
3 – Not scaring people:
“The companions of Muhammad (peace and blessings of Allaah be upon him) said that they were travelling with the Prophet (peace and blessings of Allaah be upon him), and a man among them fell asleep. Some of them got a rope and tied him up, and he got scared. The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘It is not permissible for a Muslim to frighten another Muslim.’” (Narrated by Abu Dawood).
4 – Mocking people by winking behind their backs or making snide remarks :
Allaah has forbidden such behaviour in the aayah (interpretation of the meaning): “O you who believe! Let not a group scoff at another group; it may be that the latter are better than the former. Nor let (some) women scoff at other women, it may be that the latter are better than the former. Nor defame one another, nor insult one another by nicknames. How bad is it to insult one’s brother after having Faith”[al-Hujuraat 49:11]
Ibn Katheer said in his Tafseer: “What is meant here is looking down on them, belittling them or making fun of them. This is haraam and is counted as one of the characteristics of the hypocrites.”
The Prophet (peace and blessings of Allaah be upon him) said, “Do not express malicious joy towards your brother’s misfortune, for Allaah may have mercy on him and you may be stricken by the thing you made fun of.” (Narrated by al-Tirmidhi).
The Prophet (peace and blessings of Allaah be upon him) said: “The Muslim is the brother of another Muslim, he does not wrong him, let him down or look down upon him. Taqwa (piety, awareness and fear of Allaah) is here” – and he pointed to his chest three times – “It is sufficient evil for a man to look down upon his Muslim brother. Every Muslim is sacred to another Muslim, his blood, his property and his honour.” (Narrated by Muslim)
5 – The jokes should not be excessive:
Some people joke too much and it becomes a habit for them. This is the opposite of the serious nature which is the characteristic of the believers. Joking is a break, a rest from ongoing seriousness and striving; it is a little relaxation for the soul. ‘Umar ibn ‘Abd al-‘Azeez (may Allaah have mercy on him) said: “Fear joking, for it is folly and generates grudges.”
Imaam al-Nawawi (may Allaah have mercy on him) said: “The kind of joking which is forbidden is that which is excessive and persistent, for it leads to too much laughter and hardening of the heart, it distracts from remembrance of Allaah, and it often leads to hurt feelings, generates hatred and causes people to lose respect and dignity. But whoever is safe from such dangers, then that which the Messenger of Allaah (peace and blessings of Allaah be upon him) used to do is permissible for him.”
6 – Acknowledging people’s status:
Some people may joke with everyone indiscriminately, but scholars and the elderly have rights, so you have to be aware of the character of the person with whom you are dealing. You should not joke with ignorant people, fools or people whom you do not know.
With regard to this matter, ‘Umar ibn ‘Abd al-‘Azeez said: “Fear joking, for it undermines chivalry and manliness.”
Sa’d ibn Abi Waqqaas said: “Set a limit to your jokes, for going to extremes makes you lose respect and incites the foolish against you.”
7 – The amount of joking should be like the amount of salt in one’s food:
The Prophet (peace and blessings of Allaah be upon him) said: “Do not laugh too much, for laughing too much deadens the heart.” (Saheeh al-Jaami’, 7312)
8 – It should not involve backbiting:
The Prophet (peace and blessings of Allaah be upon him) said: “[Backbiting is] your mentioning about your brother something that he dislikes.” (Narrated by Muslim)
9 – Choosing appropriate times for joking.
A man said to Sufyaan ibn ‘Uyaynah (may Allaah be pleased with him), “Joking is not right, it is to be denounced.” He replied, “Rather it is Sunnah, but only for those who know how to do it and do it at the appropriate time.”
Bilaal ibn Sa’d said: “I saw them [the Sahaabah] jokingly pretending to fight over some goods, and laughing with one another, but when night came they were like monks.”
Ibn ‘Umar (may Allaah be pleased with him) was asked, “Did the Companions of the Prophet (peace and blessings of Allaah be upon him) laugh?” He said, “Yes, and the faith in their hearts was like mountains.”
So you have to follow the example of such people, who were hard workers by day and devoted worshippers by night.
Alhamdulillah Allaah wa salla Allahu Ala Rasulihi wa Aalihi Wa Sahbihi