The adverb rendered “hard of hearing,” “dully,” or “heavily” portrays a state in which the ears are not functioning as they should for spiritual perception. Scripture employs it twice—both times in the same prophetic quotation—to underline the tragedy of willful spiritual obtuseness.

Usage in the New Testament

• Matthew 13:15

“For this people’s heart has grown dull; their ears are hard of hearing, and they have closed their eyes; otherwise they might see with their eyes, hear with their ears, understand with their hearts, and turn, and I would heal them.”

• Acts 28:27

“For this people’s heart has grown dull; their ears are hard of hearing, and they have closed their eyes; otherwise they might see with their eyes, hear with their ears, understand with their hearts, and turn, and I would heal them.”

Both citations repeat Isaiah 6:9-10 and emphasize culpable resistance to divine revelation.

Septuagint and Intertextual Background

In Isaiah 6 the prophet is commissioned to preach to a nation that will not respond; the Greek translation employs the same adverb. Jesus and Paul, by echoing Isaiah, affirm continuity between Israel’s ancient unbelief and the rejection of the Messiah and His apostolic witnesses. The imagery of weighted, sluggish ears is therefore rooted in covenant history and prophetic warning.

The Motif of Spiritual Hardness

1. Volitional dullness: The people “have closed their eyes,” highlighting an act of will rather than a mere incapacity.
2. Judicial consequence: Persistent refusal to heed God leads to further insensitivity (compare Romans 1:24-28).
3. Merciful purpose: The prophetic lament is framed by the divine desire to heal; repentance remains possible if the hardened condition is forsaken.

Christ’s Teaching and the Kingdom

Matthew places the quotation amid the Parable of the Sower. The term underscores why many listeners fail to grasp “the mysteries of the kingdom of heaven” (Matthew 13:11). Fruitfulness in the parable is tied to receptive ears; the heavy-eared hearer exemplifies soil where the word cannot penetrate deeply.

Paul’s Ministry and Jewish-Gentile Dynamics

In Rome, Paul cites the same text when a segment of the synagogue rejects the gospel. The adverb marks the decisive turning point: “Therefore I want you to know that God’s salvation has been sent to the Gentiles, and they will listen!” (Acts 28:28). The contrast between heavy-eared Israel and listening Gentiles advances the unfolding plan revealed in Acts 1:8 and Romans 11:11-12.

Pastoral and Devotional Implications

• Self-examination: Believers are warned against complacency that leads to dulled perception (Hebrews 5:11).
• Cultivation of hearing: Regular engagement with Scripture, prayer, and obedient response keeps the spiritual senses sharp (James 1:22-25).
• Intercession: The text fuels prayer that God would open ears and hearts of those yet unreceptive (Ephesians 1:17-18).

Historical Reception

Early church teachers such as Chrysostom saw in these verses proof that the problem lay not in Christ’s message but in listeners’ unwillingness. Reformers applied the passage to critique formalism devoid of heartfelt faith, while evangelicals have employed it in calls to revival and missions.

Related Biblical Themes

Hearing and Doing (Deuteronomy 6:4; Matthew 7:24-27)

Hardness of Heart (Exodus 8:15; Mark 6:52)

Blinded Eyes (2 Corinthians 4:4)

Repentance and Healing (2 Chronicles 7:14; 1 Peter 2:24)

Ministry Significance Today

The word reminds preachers that faithful proclamation must proceed even when audiences appear unresponsive. It assures missionaries that rejection is foreseen in Scripture yet does not nullify the power of the gospel. For congregations it is a summons to maintain tender consciences, attentive ears, and ready obedience so that the promise “I would heal them” may be personally and corporately realized.