By keeping the heart, we mean the diligent and constant use of all holy means to preserve the soul from sin and maintain its sweet and free communion with God. I say constant, for the reason added in the text extends the duty to all of the states and attitudes of a Christian's life, and makes it always binding. If the heart must be kept, because out of it are the issues of life, then as long as these issues of life flow out of it, we are obliged to keep it.