You mean America has sold weapons to the Muslim Brotherhood before? Which administration?
Egypt is not presently under the control of the MB, although it may very well end up there. Of course, this has always been true, and is a potential problem with arms sales to any Muslim state.
Look at the arms and military aid we gave to the Shah, all of which eventually wound up in the mullah’s hands. Or Pakistan, which could be taken over by the MB or its equivalent at any time. Or Afghanistan, which might be taken over by the Taliban again.
But saying we are selling arms to the MB is at present untrue.