Charles H. Spurgeon on Psalms 27:8

When thou saidst, etc. Now God then speaks to the heart to pray when not only he puts upon the duty by saying to the conscience, This thou oughtest to do; but God's speaking to pray is such as his speech at first was, when he made the world, when he said, "Let there be light, and there was light:" so he says, let there be a prayer, and there is a prayer; that is, he pours upon a man a spirit of grace and supplication, a praying disposition; he puts in motives, suggests arguments and pleas to God; all which you shall find come in readily, and of themselves, and that likewise with a quickening heat and enlargement of affection, and with a lingering and longing, and restlessness of spirit to be alone, to pour out the soul to God, and to vent and form those motions and suggestions into a prayer, till you have laid them together, and made a prayer of them. And this is a speaking to the heart. Observe such times when God doth thus, and neglect them not, then to strike whilst the iron is hot; thou hast then his ear; it is a special opportunity for that business, such a one as thou mayest never have the like. Suitors at court observe molissima fandi tempora, their times of begging when they have kings in a good mood, which they will be sure to take the advantage of; but especially if they should find that the king himself should begin of himself to speak of the business which they would have of him: and thus that phrase of Ps 10:17, that God prepares the heart, is understood by some, that God prepares the heart, and causeth the ear to hear; that is, he fashions it and composes it into a praying frame. And sure it is a great sign that God means to hear us when himself shall thus indite the petition. Thomas Goodwin.