Chapter XXXVI. Of the value of short and silent prayer. Wherefore we ought to pray often but briefly, lest if we are long about it our crafty foe may succeed in implanting something in our heart. For that is the true sacrifice, as “the sacrifice of God is a broken spirit.” This is the salutary offering, these are pure drink offerings, that is the “sacrifice of righteousness,” the “sacrifice of praise,” these are true and fat victims, “holocausts full of marrow,” which are offered by contrite and humble hearts, and which those who practise this control and fervour of spirit, of which we have spoken, with effectual power can sing: “Let my prayer be set forth in Thy sight as the incense: let the lifting up of my hands be an evening sacrifice.” 1659 But the approach of the right hour and of night warns us that we ought with fitting devotion to do this very thing, of which, as our slender ability allowed, we seem to have propounded a great deal, and to have prolonged our conference considerably, though we believe that we have discoursed very little when the magnificence and difficulty of the subject are taken into account. With these words of the holy Isaac we were dazzled rather than satisfied, and after evening service had been held, rested our limbs for a short time, and intending at the first dawn again to return under promise of a fuller discussion departed, rejoicing over the acquisition of these precepts as well as over the assurance of his promises. Since we felt that though the excellence of prayer had been shown to us, still we had not yet understood from his discourse its nature, and the power by which continuance in it might be gained and kept. 1659     Ps. l. (li.) 19, 21; xlix. (l.) 23; lxv. (lxvi.) 15; cxl. (cxli.) 2 .