Isaiah offered to sing a song for his good friend about his friend"s "vineyard," a figure for one"s bride (cf. Song of Solomon 1:6; Song of Solomon 8:12). Actually, this song contains a harsh message about another person and His "vineyard," namely: Yahweh and Israel. Isaiah painted a picture of a man cultivating his relationship with his wife, only to have her turn out to be disappointing. But, as would shortly become clear, he was really describing God"s careful preparation of Israel to bring forth spiritual fruit. The man double-fenced his vineyard and built a watchtower and a wine vat (storage tank) in it, indicating that He intended it to satisfy Him for a long time. Yet all His work was for naught; His finest vines (Heb. sorek) disappointed Him. Ezekiel observed that if a vine does not produce fruit, it is good for nothing ( Ezekiel 15:2-5; cf. John 15:6). [source][source][source]