'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.