An explanation for not contributing to a cause or organization, or an excuse not to donate or participate in anything. Campaigns for civic and charitable causes like the Red Cross and Community Chest were once far more prevalent at places of business than they now are, and people routinely made donations. Someone who was approached at home or elsewhere could have a valid excuse of “I gave through the office.”By extension, the phrase came to be used to slough off any kind of request. For example, someone who asked for a $20 loan might have been met with “Sorry, I gave at the office.” An old chestnut of a joke tells about the man who was lost on a camping trip. Rescuers scoured the wilderness until a medical emergency team finally spotted a solitary figure across a wide chasm. “Charlie Smith,” someone shouted,” “is that you?” “Yes, it is,” came the reply. “Who are you?” “We're from the Red Cross.” “I gave through the office!” Charlie shouted back.