بسم الله الرحمن الرحيم
Shaykh Uthaymeen – Rahimahullah -was asked a question by a group of youth who pray, fast and perform what they are able from (various) acts of worship – They said: during our rest, we joke a lot what is the ruling on this?
The Shaykh began by making dua for them:
Firstly we ask Allah – Glorified and Most High – for thabaat (steadfastness) for these brothers upon that which they perform from acts of worship and that HE makes it in the manner in which HE is pleased with and that it is in accordance to the guidance of the prophet – peace and blessings upon him and upon his family – with out going over bounds and without deficiency.
We say about your legislated acts of worship be steadfast upon them. As for joking after that; then there is no good in lots of joking indeed it has been said: “Joking in speech is like salt in food, the food is not sound without it and the food is not sound if there’s too much salt”
If there is a person who is excessive in joking he may speak about his brother with distasteful expressions which are not befitting. And it is possible that he will arrive at what is worse than that; his speech may mock something from the acts of worship or from the religion. And this is extremely dangerous, indeed it could result in disbelief. And refuge is sought with Allah, so upon them is that they joke moderately without excessiveness.
Slightly paraphrased from Shaykh Uthaymeen’s Fataawa Noor ala ad-Darb vol 12 page 687