A.B. Simpson explores the profound teachings of Isaiah on prayer, emphasizing that God is both the Hearer and Answerer of our prayers, always attentive to our needs even before we ask. He highlights the hindrances to prayer, such as sin and indolence, and illustrates the importance of fervent, active prayer as a means of spiritual engagement. Simpson also presents Jesus as the ultimate Intercessor, whose ministry of prayer empowers believers to engage in persistent prayer for God's purposes. He encourages the faithful to approach God with confidence, claiming His promises, and to seek Him earnestly, especially in repentance, as the foundation for effective prayer.