Charles H. Spurgeon on Psalms 66:9

Which holdeth our soul in life. At any time the preservation of life, and especially the soul's life, is a great reason for gratitude but much more when we are called to undergo extreme trials, which of themselves would crush our being. Blessed be God, who, having put our souls into possession of life, has been pleased to preserve that heaven given life from the destroying power of the enemy. And suffereth not our feet to be moved. This is another and precious boon. If God has enabled us not only to keep our life, but our position, we are bound to give him double praise. Living and standing is the saint's condition through divine grace. Immortal and immoveable are those whom God preserves. Satan is put to shame, for instead of being able to slay the saints, as he hoped, he is not even able to trip them up. God is able to make the weakest to stand fast, and he will do so.