John Gills Exposition of the Bible Commentary - Psalms 139:16
Thine eyes did see my substance, yet being unperfect ,.... The word F17 גלמי "informe meum", Montanus; "glomus meam", Michaelis. for "substance" signifies a bottom of yarn wound up, or any rude or unformed lump; and designs that conglomerated mass of matter separated in the womb, containing all the essentials of the human frame, but not yet distinguished or reduced into any form or order; yet, even when in this state, the eyes of the Lord see it and all its parts distinctly; and... read more
Matthew Henry's Complete Commentary - Psalms 139:7-16
It is of great use to us to know the certainty of the things wherein we have been instructed, that we may not only believe them, but be able to tell why we believe them, and to give a reason of the hope that is in us. David is sure that God perfectly knows him and all his ways, I. Because he is always under his eye. If God is omnipresent, he must needs be omniscient; but he is omnipresent; this supposes the infinite and immensity of his being, from which follows the ubiquity of his presence;... read more