Here the word "your" refers to Jesus and is singular. When you translate this, use the pronoun "your" because this is a quote from a prophet, and he did not use Jesus's name. (See: [[rc://en/ta/man/translate/figs-you]])
Doing this represents preparing the people for the Lord's arrival. Alternate translation: "will prepare the people for your arrival" (See: [[rc://en/ta/man/translate/figs-metaphor]])