My substance was not hid from thee - Thou didst see it; thou didst understand it altogether, when it was hidden from the eyes of man. The word “substance” is rendered in the margin, “strength” or “body.” The Septuagint, the Latin Vulgate, the Syriac, the Arabic, and Luther render it, “my bone,” or “my bones.” The word properly means strength, and then anything strong. Another form of the word, with different pointing in the Hebrew, means a bone, so called from its strength. The allusion here is to the bodily frame, considered as strong, or as that which has strength. Whatever there was that entered into and constituted the vigor of his frame, the psalmist says, was seen and known by God, even in its commencement, and when most feeble. Its capability to become strong - feeble as it then was - could not even at that time be concealed or hidden from the view of God.
When I was made in secret - In the womb; or, hidden from the eye of man. Even then thine eye saw me, and saw the wondrous process by which my members were formed.
And curiously wrought. - Literally, “embroidered.” The Hebrew word - רקם râqam - means to deck with color, to variegate. Hence, it means to variegate a garment; to weave with threads of various colors. With us the idea of embroidering is that of working various colors on a cloth by a needle. The Hebrew word, however, properly refers to the act of “weaving in” various threads - as now in weaving carpets. The reference here is to the various and complicated tissues of the human frame - the tendons, nerves, veins, arteries, muscles, “as if” they had been woven, or as they appear to be curiously interweaved. No work of tapestry can be compared with this; no art of man could “weave” together such a variety of most tender and delicate fibres and tissues as those which go to make up the human frame, even if they were made ready to his hand: and who but God could “make” them? The comparison is a most beautiful one; and it will be admired the more, the more man understands the structure of his own frame.
In the lowest parts of the earth - Wrought in a place as dark, as obscure, and as much beyond the power of human observation as though it had been done low down beneath the ground where no eye of man can penetrate. Compare the notes at Job 28:7-8.