Do I have to give maaser from money that was given to me but for a specific purpose? For example, If one is divorced, and the ex does not pay child support, however he sent a certain amount of money to pay for half of the child’s passport..
You do not have to give maaser from the money that is given specifically for child support, because the money wasn’t given to you, but to your children for their needs. This is especially true since it was given in order for you to do something specific for your child, i.e. make him a passport. Therefore, you don’t have to take of maser from it.
Mishpat Utzedaka 5 ftnt. 26.