What is the ruling on collecting money in mosques during Friday prayers?

It is disliked to ask [for charity] in the mosque, and it may even reach the level of prohibition. One who asks should not be given. However, it is permissible to give charity to the poor person or to someone for whom the Imam (Khatib) has asked in the mosque. Scholars have agreed on the prohibition of begging unless there is a necessity. They have differed on the issue of begging by one who is able to earn a living. The soundest opinions are that it is forbidden, or that it is permissible with dislike, under three conditions: that one does not humiliate oneself, that one does not persist in asking, and that one does not harm the one being asked. Otherwise, it is forbidden by consensus.