New Defender's Study Bible Notes
5:1 vineyard. The “vineyard” in this song represents Israel (Isaiah 5:7), a figure that was later appropriated by Christ (Matthew 21:33-45). The “pleasant plant” in the vineyard, which represents Judah, is probably the “fig tree planted in his vineyard” (Luke 13:6). Sadly, however, the vineyard produced wild grapes and the fig tree was barren, so God eventually had to “lay it waste” (Isaiah 5:6).
5:7 the house of Israel. See above note for Isaiah 5:1.