Charles Ellicott Commentary Psalms 139:17

"How precious also are thy thoughts unto me, O God! How great is the sum of them!" — Psalms 139:17 (ASV)

Precious. —Rather, weighty, the first meaning of the word. The parallelism requires this, as also the distinctive word for “thoughts,” for which see Psalms 139:2. We have here the antithesis to that verse: while the Divine penetration discovers the most intimate thought of man, man finds God’s secrets incomprehensible.