That portion of the Marriage Service in which the contracting parties answer "I will" to the questions, "N. wilt thou have this woman to thy wedded wife" and "N. wilt thou have this man to thy wedded husband." This seems to be the remains of the old form of espousals, which was different and distinct from the Office of Marriage, and which was often performed some weeks or months or perhaps years before. Something similar to what is now called "engagement," only that it had the blessing of Mother Church upon it. In the Greek Church at the present time there are still two different offices, viz.: the one of espousals and the other of marriage, which are now performed on the same day, although formerly on different days.

Bibliography Information
Miller, William James. Entry for 'Espousal'. The American Church Dictionary and Cyclopedia. https://www.studylight.org/dictionaries/eng/acd/e/espousal.html. 1901.

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The American Church Dictionary and Cyclopedia

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Espousal