A.T. Robertson Commentary Romans 8:20

"For the creation was subjected to vanity, not of its own will, but by reason of him who subjected it, in hope" — Romans 8:20 (ASV)

Was subjected (υπεταγη). Second aorist passive indicative of υπατασσω (cf. verse 7).

To vanity (τη ματαιοτητ). Dative case. Rare and late word, common in LXX. From ματαιος, empty, vain. Ephesians 4:17; 2 Peter 2:18.

Not of its own will (ουχ εκουσα). Common adjective, in N.T. only here and 1 Corinthians 9:27. It was due to the effect of man's sin.

But by reason of him (αλλα δια τον). Because of God.

In hope that (εφ' ελπιδ οτ). Note the form ελπιδ rather than the usual ελπιδ and so εφ'. Hοτ can be causal "because" instead of declarative "that."