Albert Barnes Commentary Luke 1:38

"And Mary said, Behold, the handmaid of the Lord; be it unto me according to thy word. And the angel departed from her." — Luke 1:38 (ASV)

And Mary said, Behold the handmaid. This was an expression of resignation to the will of God, and of faith in the promise. To be the hand-maid of the Lord is to be submissive and obedient, and is the same as saying, "I fully credit all that is said, and am perfectly ready to obey all the commands of the Lord."