In Psalm 37:31, 'the law of his God is in his heart' directly parallels 'your law is within my heart'.

Psalm 112:1 also speaks of delighting in God's commandments — a direct thematic parallel to delighting in God's will.

Psalm 119:16 echoes the same delight in God's statutes — reinforcing the theme of joyful obedience.

Psalm 119:24 declares God's testimonies are his delight — mirroring the psalmist's delight in God's will.

Psalm 119:47 finds delight in God's commandments — a close parallel to the delight expressed in Psalm 40:8.

Psalm 119:92 says God's law was his delight in affliction — similar to the psalmist's delight in God's will.

Psalm 1:2 says the blessed man's delight is in the law of the LORD — directly parallel to delighting in God's will and law in heart.

Psalm 19:8 says the LORD's precepts rejoice the heart — the law brings joy, matching the psalmist's delight.

Psalm 119:11 says 'I have stored up your word in my heart' — directly parallel to 'your law is within my heart.'

Psalm 119:70 contrasts the wicked's unfeeling heart with 'I delight in your law' — the same delight in law as in Psalm 40:8.

Psalm 119:167 says 'I love your testimonies exceedingly' — love for God's law parallels delight in doing His will.

In Jeremiah 15:16, the prophet also finds God's words as joy and delight of heart, echoing the same internalized love for God's law.

In Jeremiah 31:33, God promises to write his law on hearts, fulfilling the ideal of law within the heart.

In John 4:34, Jesus says doing God's will is his food, paralleling the delight in doing God's will expressed here.

In Romans 7:22, Paul says he delights in God's law in his inner being, directly echoing this verse's language.

Mark 14:36 shows Jesus submitting to the Father's will — the ultimate fulfillment of delighting to do God's will from Psalm 40:8.

Jeremiah 6:10 describes people who take no pleasure in God's word — the opposite of the delight in doing God's will in Psalm 40:8.

In Luke 22:42, Jesus prays 'not my will but yours be done' — directly embodying the delight in doing God's will from Psalm 40:8.

Isaiah 51:7 describes those who have God's law in their hearts — the exact same phrase as Psalm 40:8, linking delight to endurance.

In John 5:30, Jesus says he seeks not his own will but the Father's — a direct parallel to the psalmist's delight in doing God's will.

In John 6:38, Jesus declares he came to do the Father's will, not his own — echoing the delight in God's will from Psalm 40:8.

In John 14:31, Jesus says he does as the Father commanded — directly reflecting the delight in doing God's will from Psalm 40:8.

In Deuteronomy 6:6, God commands His words to be on your heart — the same internalization of law that the psalmist delights in.

In 2 Corinthians 3:3, the new covenant writes God's law on human hearts by the Spirit, echoing the internal law theme.

In Matthew 3:15, Jesus fulfills all righteousness — a direct embodiment of the delight in doing God's will from Psalm 40:8.

Luke 2:49 shows Jesus prioritizing his Father's business — reflecting the delight in doing God's will from Psalm 40:8.

Luke 6:45 teaches that the heart's treasure produces actions — aligning with the law in the heart leading to delight in Psalm 40:8.

In Luke 12:50, Jesus expresses eagerness to undergo his baptism of suffering — echoing the psalmist's delight in doing God's will.

Matthew 6:10 prays for God's will to be done — echoing the delight in doing God's will from Psalm 40:8.

Proverbs 21:15 says doing justice brings joy to the righteous — paralleling the delight in doing God's will from Psalm 40:8.

Job 23:12 treasures God's words more than food — akin to having God's law within the heart, though Job's context is suffering.

Isaiah 42:21 describes the LORD magnifying his law — aligning with the delight in God's law expressed in Psalm 40:8.

Proverbs 4:21 urges keeping wisdom's words within your heart — echoing the internalization of God's law in Psalm 40:8.

In Proverbs 3:1, keeping commandments in the heart is urged, similar to the internal law here.