Strong’s Greek 5338 (φέγγος) denotes the visible radiance emitted by a heavenly body—a brightness perceptible to human sight rather than an abstract notion of “light” as enlightenment. It therefore emphasizes literal luminosity, making it well suited to prophetic scenes in which the Creator demonstrates His sovereignty by dimming what He originally commanded to shine (Genesis 1:16).

Occurrences in the New Testament

1. Matthew 24:29 – “Immediately after the tribulation of those days: ‘The sun will be darkened, and the moon will not give its light (φέγγος); the stars will fall from the sky, and the powers of the heavens will be shaken.’”
2. Mark 13:24 – “But in those days, after that tribulation: ‘The sun will be darkened, and the moon will not give its light (φέγγος).’”

In both verses φέγγος appears in Jesus’ Olivet Discourse, forming part of a triad of cosmic disturbances that herald His visible return.

Old Testament Background

Jesus’ words echo prophetic descriptions of the “day of the Lord.” Isaiah 13:10, Ezekiel 32:7-8, Joel 2:10, and Amos 8:9 foretell a withdrawal of solar and lunar brilliance as a sign of divine judgment. By using φέγγος, the Gospel writers deliberately connect Christ’s teaching with these earlier oracles, underscoring the unity of redemptive history.

Eschatological Significance

1. Certainty of Fulfillment: Because the same mouth that calmed Galilee foretells the dimming of the moon, believers can be confident that these cosmic signs will literally occur (Matthew 24:35).
2. Public Visibility: The removal of φέγγος ensures that Christ’s return will not be hidden or metaphorical; it will be as unmistakable as the darkened skies themselves (Revelation 1:7).
3. Divine Disruption of the Ordinary: The cessation of moonlight signals that history is reaching its climactic transition, when temporal patterns give way to eternal realities (2 Peter 3:10-13).

Theology of Light and Darkness

Throughout Scripture light represents life, joy, and divine presence, while darkness often symbolizes judgment and separation. φέγγος, as the literal gleam of the moon, stands at the intersection of these motifs. When its shining ceases, humanity is confronted with the sobering truth that earthly lights are temporary and derivative, pointing beyond themselves to the uncreated glory of God (1 Timothy 6:16; Revelation 21:23).

Christological Focus

The dimming of φέγγος magnifies Jesus Christ as “the true light that gives light to every man” (John 1:9). When lesser luminaries fail, He alone remains radiant. Thus the prophecy drives readers to rely on the eternal Light rather than on created reflections.

Pastoral and Practical Implications

• Watchfulness: The impending loss of moonlight presses believers to heed Jesus’ exhortation, “Therefore keep watch, because you do not know on what day your Lord will come” (Matthew 24:42).
• Evangelistic Urgency: If even the heavens will testify to Christ’s lordship, the church must proclaim that lordship while “it is still day” (John 9:4).
• Spiritual Priorities: Earthly securities, like recurring lunar cycles, can be suspended at God’s command; wise disciples store up treasure in heaven (Matthew 6:19-21).

Historical Interpretation

Early patristic writers such as Justin Martyr and Tertullian read these verses literally, linking them to Isaiah’s oracles and viewing the darkening as a precursor to the resurrection of the saints. Medieval commentators often saw a dual sense: literal cosmic upheaval and symbolic judgment upon worldly powers. Reformation expositors returned to a predominantly literal expectation, reinforcing confidence in the text’s straightforward meaning.

Doctrinal Connections

• Divine Sovereignty: φέγγος serves as a tangible reminder that “by Him all things were made” and by Him they continue or cease (Colossians 1:16-17).
• Eschatological Hope: The prophecy sustains the blessed hope of Titus 2:13, anchoring it in observable events rather than speculative mysticism.
• Continuity of Revelation: The shared imagery between Old and New Testaments attests to the coherence of Scripture, reinforcing trust in its unified message.

Conclusion

Though φέγγος appears only twice, its strategic placement in the Olivet Discourse turns the ordinary glow of the moon into a powerful eschatological sign. When that glow is withheld, creation itself will declare that the Judge is at the door, urging every generation to live in readiness, holiness, and steadfast hope.