John Calvin Commentary Psalms 141:9

"Keep me from the snare which they have laid for me, And from the gins of the workers of iniquity." — Psalms 141:9 (ASV)

Keep me, and so forth. He acknowledges that he is trapped in the snares of his enemies, unless set free by a higher hand. In praying to God in the difficult circumstances to which he was reduced, he shows what a high value he placed on what God's mercy could accomplish, as he says elsewhere, that the issues from death belong to him (Psalms 68:20).

God often delays intervening, so that the deliverance may be more remarkable; and afterwards he makes the schemes of the wicked recoil upon their own heads. It seems absurd to refer the pronoun his to Saul, as if the meaning were that Doeg and others of that character would fall into the snares of Saul.

It would seem that God is the one intended. First, he had spoken of being preserved by God from the traps of the wicked; and now, to these snares which the wicked spread for the upright, he contrasts the snares with which God catches the crafty in their own schemes. And since the number of his enemies was great, he uses the expression, let them fall together, for escape would have been impossible if he had not been persuaded that it was easy for God to overthrow any combined force and array of men.

What follows can be understood in two ways. Many read it as, I shall always pass. But we may suppose the order of the words is changed, and read it as, until I pass. He prays that his enemies would be held in the snare until he escaped safely.