When I hear the word "commission," the first thing that comes to my mind is the commission military officers receive when they enter into service. Commissioned officers derive their authority directly from a sovereign power and, as such, hold a commission charging them with the duties and responsibilities of a specific office or position.
Both the enlisted and officers affirm their service by reciting similar oaths. They both begin with: "I, [state our name ], do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; [and] that I will bear true faith and allegiance to the same." Now, from that point, the oaths differ a little bit.
The Enlisted then affirm: "I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice." Officers, however finish their oath by stating: "I take this obligation freely, without any mental reservation or purpose of evasion; and that I will, well and faithfully discharge the duties of the office on which I am about to enter. So help me God."