When I said, my foot slippeth,.... There is no ground for me to stand upon; all is over with me; there is no hope nor help for me; I am just falling into ruin and destruction: such will be the desperate case of the church, at the time before referred to: thy mercy, O Lord, held me up; the extremity of his people is the Lord's opportunity; then is his set time to arise, and have mercy on them; then mercy steps in, lays a solid ground and foundation for hope, and holds up in its arms a sinking people, and revives a dying cause.