I believe the answer is: Necessary and Proper Clause"
Necessary and Proper Clause give the congress with the ability to exercise the powers that are not explicitly stated in the constitution as long as they are deemed as necessary and proper for the government to achieve its goal.
From this, they create a list of implied powers which are not exist in constitution but are 'needed' in order for them to fulfill the duties that directly stated in the constitution. Examples of implied powers are government's ability to collect taxes and create government agencies.
