12 “Which deliverest the poor from him that is too strong for him; yea, the poor and needy from him that spoils him.”...Who that deliverest, but He who is Strong in hand? Even that David shall deliver the poor from him that is too strong for him. For the devil was too strong for you, and held you, because he conquered you, when you consented unto him. But what has the Strong in hand done? “No man enters into a strong man's house, to spoil his goods, except he first bind the strong man.” By His own Power, most Holy, most Magnificent, has He bound the devil by pouring forth the weapon to stop the way against him, that He may deliver the poor and needy, to whom there was no helper. For who is your helper but the Lord to whom you say, “O Lord, My Strength, and My Redeemer.” If you will presume of your own strength, thereby will you fall, whereof you have presumed: if of another's, he would lord it over you, not succour you. He then alone is to be sought Who has redeemed them, and made them free, and has given His Blood to purchase them, and of His servants has made them His Brethren....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)