As in poetry, so in prayer, the whole subject matter should be furnished by the heart, and the understanding should be allowed only to shape and arrange the effusions of the heart in the manner best adapted to answer the end designed. From the fullness of a heart overflowing with holy affections, as from a copious fountain, we should pour forth a torrent of pious, humble, and ardently affectionate feelings; while our understandings only shape the channel and teach the gushing streams of devotion where to flow, and when to stop.