Shaving. Being forced to shave was a mark of humiliation (7:20). In some nations of that time, the hair of slaves was shaved in a particular way to identify them as their owner’s property.
Ten acres of vineyard would normally produce 10,000 gallons (37,850 liters) of wine yearly. Isaiah says that the Lord’s judgment upon Israel would be so severe that ten acres of vineyard would produce only one bath, or six gallons (23 liters). See 5:10.
The tinkling of feet mentioned in 3:16 is probably the ankle bracelets many women wore in the ancient world. They were usually made of bronze and were attached permanently.
Pruning hooks (2:4) were used to cut away newly formed leaves and shoots from grape vines. The blade curved into a sharp hook at the tip, allowing it to capture and cut new growth more easily than a straight blade.
The Holy One of Israel is Isaiah’s main title for God. The phrase occurs 25 times in the book, but rarely elsewhere in the Bible. The word “holy” describes the Lord’s absolute moral purity and his being far greater than all that he has created.