Psalms 31:4

Pull me out of the net that they have laid privily for me
The Ziphites, and Saul, and his men; the former intending treacherously to betray him, and the latter encompassing him about in order to take him; and such was his danger and difficulty, that he saw none but God could deliver him; and he it is that breaks the nets of men, and the snares of the devil, which they secretly lay for the people of God, that they may stumble, and fall, and be taken, and delivers them out of them;

for thou [art] my strength;
the author, giver, and maintainer, both of his natural and spiritual strength; and who was able, and was only able, to pull him out of the net, and extricate him out of the difficulties in which he was.