11:21 The strong one armed - The devil, strong in himself, and armed with the pride, obstinacy, and security of him in whom he dwells.

Luke 11:21 Parallel Commentaries

A Greater than Solomon
The second thought that comes to one's mind is this: notice the self-consciousness of the Lord Jesus Christ. He knows who He is, and what He is, and He is not lowly in spirit because He is ignorant of His own greatness. He was meek and lowly in heart--"Servus servorum," as the Latins were wont to call Him, "Servant of servants," but all the while He knew that He was Rex regum, or King of kings. He takes a towel and He washes His disciples' feet; but all the while He knows that He is their Master …
Charles Haddon Spurgeon—Spurgeon's Sermons Volume 27: 1881

The Ministration of the Spirit and Prayer
"If ye, being evil, know how to give good gifts to your children; how much more shall your Heavenly Father give the Holy Spirit to them that ask Him?"--LUKE xi. 13. Christ had just said (v. 9), "Ask, and it shall be given": God's giving is inseparably connected with our asking. He applies this especially to the Holy Spirit. As surely as a father on earth gives bread to his child, so God gives the Holy Spirit to them that ask Him. The whole ministration of the Spirit is ruled by the one great law: …
Andrew Murray—The Ministry of Intercession

Because of his Importunity
"I say unto you, Though he will not rise and give him, because he is his friend, yet because of his importunity he will arise and give him as many as he needeth."--LUKE xi. 8. "And He spake a parable unto them, to the end, they ought always to pray and not to faint.... Hear what the unrighteous judge saith. And shall not God avenge His own elect, which cry to Him day and night, and He is long-suffering with them? I tell you that He will avenge them speedily."--LUKE xviii. 1-8. Our Lord Jesus …
Andrew Murray—The Ministry of Intercession