Isaiah 48:4

Because I knew that thou art obstinate, and thy neck is an iron sinew, and thy brow brass;

God fully knew His professed people Israel to be obstinate, and the picture of a neck like an iron sinew and a brow like brass portrays stubborn resistance to Him. Because of that stubborn and treacherous character He announced events from the beginning, knowing the people would otherwise credit their idols rather than Him for what came to pass. The same description applies to those who have received truth repeatedly, line upon line and precept upon precept, yet refuse to hear and receive God's testimonies of warning. They dismiss the voice of His Spirit as nothing, resist His work, and hinder His cause with misrepresentation, falsehood and heresy.

The verse belongs to a passage — its chapter and, more broadly, chapters 48 through 52 together — that sets forth the work of God's messengers as the work to be done now and relevant to present ministry. That present work is a united and determined effort in soul-saving, especially decided work in the cities without delay. It calls for increasing the number of workers, bringing in means, putting on the armor, reconsecration, and harmony with God and with Christ His only begotten Son.

Those who have means must help do this work without delay and resist the temptation to enter commercial enterprises instead of investing their means in the Lord's work. The chapter is to be studied carefully with prayer for willingness to do God's bidding, heeding twenty years of messages stressing the need to proclaim the message throughout the world.