'Impenetrable' in the Bible

Let the words of my mouth and the meditation of my heartBe acceptable and pleasing in Your sight,O Lord, my [firm, immovable] rock and my Redeemer.

The Lord is my strength and my [impenetrable] shield;My heart trusts [with unwavering confidence] in Him, and I am helped;Therefore my heart greatly rejoices,And with my song I shall thank Him and praise Him.

The Lord will give [unyielding and impenetrable] strength to His people;The Lord will bless His people with peace.

God is our refuge and strength [mighty and impenetrable],A very present and well-proved help in trouble.

On God my salvation and my glory rest;He is my rock of [unyielding] strength, my refuge is in God.

Your God has commanded your strength [your power in His service and your resistance to temptation];Show Yourself strong, O God, who acted on our behalf.

They'll cut down her forest, though it's impenetrable," declares the LORD, "for they're more numerous than locusts, and there are too many of them to count.

Wail, O cypress, for the cedar has fallen,Because the glorious trees have been destroyed;Wail, O oaks of Bashan,For the impenetrable forest has come down.