Basil of Caesarea — as excerpted in the Catena Aurea on Luke 11:1-4

“(Const. Monast. cap. 1.) There are two kinds of prayer, one composed of praise with humiliation, the other of petitions, and more subdued. Whenever then you pray, do not first break forth into petition; but if you condemn your inclination, supplicate God as if of necessity forced thereto. And when you begin to pray, forget all visible and invisible creatures, but commence with the praise of Him who created all things. Hence it is added, And he says unto them, When you pray, say, Our Father.”