Charles Ellicott Commentary Genesis 16:8

"And he said, Hagar, Sarai`s handmaid, whence camest thou? and whither goest thou? And she said, I am fleeing from the face of my mistress Sarai." — Genesis 16:8 (ASV)

From where did you come? —It is noteworthy that in these Divine communications God’s knowledge of all the circumstances is not presumed, but the person visited is guided to tell them. This adds very much to the freshness and poetry of the narrative. Here, however, in the address, Hagar, Sarai’s maid, the angel, at least, shows that he is aware who she is, and also reminds her of what she had forgotten, that in bestowing her upon Abram, Sarai did not cease to be her mistress.