In Hebrews 6:18, the two unchangeable things (God's promise and oath) give us encouragement, directly following verse 17's oath.

Hebrews 6:12 urges imitating those who inherit promises through faith and patience—the oath in 6:17 confirms that inheritance.

Hebrews 6:16 explains how oaths confirm human promises; God uses the same logic to confirm His.

In Hebrews 11:9, the 'heirs of what was promised' are exemplified by Abraham, Isaac, and Jacob living as foreigners in the land of promise.

Hebrews 10:36 shows the needed endurance to receive the promise, matching the certainty of God's oath here.

In Hebrews 1:14, angels serve those who inherit salvation — this connects to the heirs of the promise here.

Romans 11:29 says God's gifts and call are irrevocable, echoing the unchangeable purpose confirmed by oath.

In Galatians 3:29, believers are identified as Abraham's seed and heirs according to the promise, directly linking to the heirs in Hebrews 6:17.

Malachi 3:6 states God does not change, directly supporting the unchanging nature of His purpose in Hebrews.

In Jeremiah 33:21, God's covenant with David is as unbreakable as the day-night covenant, underscoring the certainty of his promise.

In Jeremiah 33:20, God's covenant with day and night is unbreakable, echoing the unchangeable nature of his oath.

In Isaiah 55:11, God's word accomplishes his purpose, reinforcing the certainty of his unchangeable will.

In Isaiah 54:9, God swears to never again flood the earth, mirroring the oath of unchangeable promise in Hebrews.

In Isaiah 46:10, God declares his counsel stands and he accomplishes all his purpose — a strong parallel to the unchangeable oath.

In Isaiah 14:27, God's purpose cannot be annulled, reinforcing the unchangeable divine counsel.

In Isaiah 14:24, God swears to his purpose, directly echoing the unchangeable oath theme in Hebrews.

In Proverbs 19:21, the Lord's purpose prevails over human plans, reinforcing the unchangeable purpose of God.

In Psalm 33:11, the Lord's plans stand firm forever — a clear parallel to the unchanging nature of God's purpose.

James 1:17 describes God as unchanging, undergirding the certainty of His promised purpose.

In Titus 3:7, believers become heirs according to hope of eternal life — this identifies the heirs of the promise in Hebrews 6:17.

In Titus 1:2, God who never lies promised eternal life before time — this directly supports the unchangeable character of his purpose.

In 1 Thessalonians 5:24, God's faithfulness to do what he says aligns with the unchangeable purpose guaranteed by oath.

In Ephesians 1:11, predestination according to God's purpose directly mirrors the unchangeable purpose in Hebrews 6:17.

Genesis 26:3 records God's promise to Isaac with an oath to Abraham, directly parallel to God confirming His purpose.

In Acts 2:30, God's oath to David about Christ's throne echoes the unchangeable purpose and oath here — both show God guaranteeing his promise.

Luke 1:73 directly mentions the oath God swore to Abraham—the same oath that guarantees God’s unchangeable purpose here.

Jeremiah 22:5 records God swearing by Himself—the same self-referential oath pattern that underlies God’s guarantee here.

Psalm 105:9 mentions God's covenant and sworn promise to Isaac—directly parallels the oath-confirmed promise in Hebrews 6:17.

Psalm 89:35 records God swearing by His holiness not to lie—direct parallel to God's oath confirming His promise.

Deuteronomy 32:40 has God swearing by His own life—direct parallel to God confirming His promise with an oath in Hebrews 6:17.

Genesis 6:6 says God regretted making humanity, contrasting with His unchanging purpose in Hebrews.

In Romans 8:17, believers are described as heirs of God and co-heirs with Christ, expanding who the heirs of the promise are.

In Romans 9:6, God's word has not failed — it illustrates the reliability of God's promise, tying to the unchangeable purpose here.

In Acts 4:28, God's predetermined plan is described — this reinforces that God's purpose is unchangeable, as in Hebrews 6:17.

John 3:33 says that receiving Christ’s testimony affirms God is true—reinforcing the reliability of God’s word and oath in Hebrews.

Jeremiah 33:26 reaffirms God's covenant with Jacob and David, showing His unwavering commitment to His promises.