It comes from Congress. We fund Civil Society NGOs as part of our foreign policy.
Sometimes it is controversial because it often supports the political opposition.
After Morsi took power in Egypt, he arrested some NGOers, including some Americans(2011). We forced him to release the Americans but they were all convicted in 2013 and sentenced to jail. The Americans were convicted in absentia.
Putin is very critical of this. Carter gave money to those in Afghanistan which lead to the Soviet invasion there. Then the NGO money went to the Orange and Velvet revolutions(Ukraine and Georgia) and probably played a part in the recent uprising in Ukraine.
And this NGO money was supporting Putin's political opposition in Russia. Putin cut off all that money and threw Pussy Riot in jail.
How about no foreign aid to any country? Taxing us and sending the money abroad is theft. Private donors could send as much as they want, and I imagine that Egypt probably wouldn’t get enough for a cup of coffee.