“Daughter Zion.” Here Jerusalem (and by extension, Judah), is referred to as the daughter of God, a use of the figure of speech hypocatastasis that brings a lot of meaning and emotion to the verse. As a daughter, God would have loved to have tenderly cared for her, but she refused His help and advice. Also as a daughter, she had cultural obligations to obey her Father and follow His ways, but she spurned her father and did whatever she wanted, which resulted in her ruin. [For more on the figure of speech hypocatastasis, see commentary on Rev. 20:2. For more on “Daughter Zion” and the Israel as the Bride, see Appendix 13, “The Bride of Christ”].
“booth...watchman’s hut.” This refers to the biblical custom of guarding the crops. Between the planting season and the harvest, farmers put up temporary shelters in their fields so they could guard their crops from thieves and pests. The booth or hut sheltered the watchman from the heat and wind. Family members would take turns manning these shelters, even spending the night there if the situation warranted it. The shelters were temporary, and after the harvest they were abandoned and soon fell into ruin, eventually even simply falling down and falling apart. Here in Isaiah 1:8, God compares Zion to one of those huts—Zion is in a state of ruin. Sometimes the watchtowers in the fields and vinyards were built to last; they were much more permanent and sturdy, and that is the kind of watchtower that is mentioned in Isaiah 5:2.
Amos prophesied about the same time as Isaiah (likely started before Isaiah started and ended before Isaiah ended), and Amos also spoke of David’s fallen “booth” (Amos 9:11), using the same word for “booth” (Hebrew: sukkah #05521 סֻכָּה) as Isaiah does. Judah was in ruins, but God says it will be restored. [For more on the Messianic Kingdom on earth, see Appendix 3, “Christ’s Future Kingdom on Earth”].