Psalm 139:16
Thine eyes did see my substance, yet being unperfect; and in thy book all my members were written, which in continuance were fashioned, when as yet there was none of them.
Cross-references
Psalm 22:9 testifies to God's care from the womb, directly paralleling the divine foreknowledge and formation here.
Psalm 71:6 also describes leaning on God from birth, reinforcing the theme of God's intimate involvement from the womb.
Psalm 56:8 also mentions God's book, recording tears rather than days, showing God's intimate record of our lives.
Exodus 32:32 refers to God's book from which Moses asks to be blotted out, connecting to the book of days written for each person.
Malachi 3:16 describes a book of remembrance, similar to the book of days here, both reflecting God's attention to His people.
Revelation 20:12 mentions books opened at judgment, expanding the book imagery to include the book of life and deeds.