In terms of the “source”, in this instance, we would regulate, within regulation, the U.S. Customs and Border Protection; they collect it from the passport upon entry, and within 15 minutes that entry record into the U.S. constitutes an exit from Canada.
Evidence of meeting #75 for Public Safety and National Security in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was goods.
A recording is available from Parliament.