In the Roman Divine Office, the first responsory of Matins on the First Sunday of Advent, Aspiciens a longe, is one of longest of the entire year, and unique in its arrangement. The responsory proper is divided into four parts, where two is standard, and three is rare; the second, third and fourth part are repeated after three different psalm verses, followed by the doxology and then the repetition of the whole first section. The Roman breviary also gives it a special significance by using it only once, where normally the responsories of a Sunday are repeated during the week. (In some other Uses, e.g. those of the Dominicans and Cistercians, it is repeated during the week, but in a shortened form.)
℟. Aspiciens a longe, ecce vídeo Dei potentiam venientem, et nébulam totam terram tegentem: * ite obviam ei, et dícite: * Nuntia nobis, si tu es ipse, * qui regnatúrus es in pópulo Israël.℣. Quique terrígenæ, et filii hóminum, simul in unum dives et pauper: ite obviam et, et dícite.
℣. Qui regis Israël, intende, qui dedúcis velut ovem Joseph: nuntia nobis, si tu es ipse.
℣. Tóllite portas, príncipes, vestras, et elevámini portæ æternáles, et introíbit Rex gloriæ, qui regnatúrus es in pópulo Israël.
Gloria Patri, et Filio, et Spiritui Sancto.
℟. Aspiciens a longe, ecce vídeo Dei potentiam venientem, et nébulam totam terram tegentem: ite obviam ei, et dícite: Nuntia nobis, si tu es ipse, qui regnatúrus es in pópulo Israël.
℣. All you that are earthborn, and you sons of men: both rich and poor together, go ye out to meet him and say.
℣. Give ear, O thou that rulest Israel: thou that leadest Joseph like a sheep; tell us if thou art the one.
℣. Lift up your gates, O ye princes, and be ye lifted up, O eternal gates: and the King of Glory shall enter in, who art to rule in the people of Israel.
Glory be unto the Father, and to the Son, and to the Holy Spirit.
Looking from afar, behold I see the power of God coming, and a cloud covering all the land: go ye to meet him and say: tell us if thou art the one, who art to rule in the people of Israel.
Today, I stumbled across this image from an antiphonary produced in central Italy (Umbria or Tuscany) in the first half of the forteenth century, with a particularly splendid initial A for the beginning of this text. (Public domain image from the website of the Cleveland Museum of Art; click to enlarge.)