The Lebanese Muslim Association says it arranged for a Christmas wish to be written in the sky above the country's biggest mosque, in response to reports it had banned Muslims from wishing people a happy Christmas.

Over the weekend, a message appeared on the Facebook page for Lakemba Mosque, saying that Muslims were forbidden from taking part in Christmas traditions or wishing people a merry Christmas.

The entry implied it was a fatwa, or Islamic ruling, and was based on a lecture given at the mosque during Friday prayers.

The Lebanese Muslim Association, which runs the mosque, says the comments were taken out of context and the group harbours no anti-Christmas sentiment.

Samier Dandan from the the Lebanese Muslim Association says a junior staff member of the association copied and pasted text from another website that the mosque had not endorsed.

"From our perspective this is an innocent mistake done by a youth member who's employed by this organisation," he said.

"We are basically not going to apologise for what I perceive to be an innocent mistake, which is not necessarily reflective of the true mindset and belief of this organisation."

This afternoon, the organisation arranged to have the words "Merry Xmas" written in the sky above Lakemba Mosque.

Earlier today, Islamic Friendship Association spokesman Keysar Trad said the fatwa was not valid, and described the Facebook remarks as damaging and divisive.

"These types of comments, unfortunately, do nothing to promote unity, and I'm glad they've been taken down," he said.

Ahmet Keskin from the Affinity Intercultural Foundation also spoke out against the comments.

"I have no problems passing on those well-wishes at times of Christmas," he said.

"We should be looking to pass on comments to build relations, so I think any opportunity that we can get it's always great to pass on those well-wishes, so that we can get closer and seek greater understanding of each other."