I do not bind myself to such words or syllables, but say my prayers in one fashion today, in another tomorrow, depending upon my mood and feeling. I stay however, as nearly as I can, with the same general thought and ideas. It may happen occasionally that I may get lost among so many ideas in one petition (of the Lord’s prayer) that I forego the other six. If such an abundance of good thoughts comes to us we ought to disregard the other petitions, make room for such thoughts, listen in silence, and under no circumstances obstruct them. The Holy Spirit himself preaches here, and one word of his sermon is far better than a thousand of our prayers.
If I have had time and opportunity to go through the Lord’s Prayer, I do the same with the Ten Commandments. I take one part after another and free myself as much as possible from distractions in order to pray. I divide each commandment into four parts, thereby fashioning a garland of four strands. That is, I think of each commandment as, first, instruction, which is really what it is intended to be, and consider what the Lord God demands of me so earnestly. Second, I turn it into a thanksgiving; third, a confession; and fourth, a prayer.
(from Martin Luther’s Works, Vol. 43, pgs. 199-201)