Charles Ellicott Commentary Psalms 119:152

"Of old have I known from thy testimonies, That thou hast founded them for ever. RESH." — Psalms 119:152 (ASV)

The more obvious rendering of this verse is, Long ago I was instructed from Your testimonies, for — not for a brief time, but for ever — You founded them, where for ever expresses indefinite past as well as indefinite future.