Jesus' Reference to Isaiah 58 in Matthew 6 Fasting
Jesus' Teaching on Fasting in Matthew 6 and its Connection to Isaiah 58
Jesus' instruction on fasting in Matthew 6:16-18 is closely tied to Isaiah 58, a chapter that critiques the Israelites' superficial fasting practices. In Matthew 6:16, Jesus warns against hypocritical fasting, saying, "Moreover when you fast, don’t be like the hypocrites, with sad faces. For they disfigure their faces, that they may be seen by men to be fasting" [5]. This warning is reminiscent of Isaiah 58:3-5, where the prophet rebukes the Israelites for their insincere fasting.
Isaiah 58:3 asks, "Why have we fasted and You do not see? Why have we humbled ourselves and You do not notice?" The people complain that their fasting is not acknowledged by God. The prophet responds that their fasting is tainted by selfish desires and oppression of others: "Behold, on the day of your fast you find your desire, And drive hard all your workers" (Isaiah 58:3) [4]. Isaiah 58:6-7 outlines the kind of fasting God desires: "Is not this the fasting that I have chosen, to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?" [1].
Jesus' teaching in Matthew 6:16-18 echoes Isaiah's emphasis on the heart's condition during fasting. Jesus contrasts the hypocrites' public display of fasting with a more private, sincere practice: "But you, when you fast, anoint your head and wash your face; so that you are not seen by men to be fasting, but by your Father who is in secret, and your Father, who sees in secret, will reward you" (Matthew 6:17-18) [2]. The connection between Matthew 6 and Isaiah 58 is not merely thematic; it reflects a deeper continuity between Jesus' teaching and the prophetic tradition.
The historical context of fasting in ancient Israel is relevant here. The Mosaic law mandated one annual fast, the Day of Atonement (Leviticus 23:26-32). Over time, the Jews observed additional fasts, particularly during the Babylonian exile (Zechariah 7:1-7; 8:19) [8, 9]. By Jesus' time, fasting had become a regular practice, often associated with prayer and repentance [3].
The key terms in Isaiah 58 and Matthew 6 highlight the importance of sincerity and inner transformation. The Hebrew term "innuy nefesh" (afflicting the soul) in Isaiah 58:3, 5 refers to the practice of fasting. The Greek term "apokruptō" (to hide) in Matthew 6:18 emphasizes the need for secrecy in fasting [1, 2].
Interpreters across traditions have recognized the connection between Isaiah 58 and Matthew 6. John Calvin notes that fasting is valuable only when accompanied by "internal affection of the heart, true dissatisfaction with sin and with one’s self, true humiliation, and true grief, from the fear of God" [11]. Similarly, Jamieson, Fausset, and Brown comment that Isaiah 58 critiques the Israelites' "dependence on mere outward forms of worship" [10].
The implications of Jesus' teaching on fasting are far-reaching. By referencing Isaiah 58, Jesus underscores the importance of aligning external practices with inner devotion. As Torrey's Topical Textbook notes, true fasting is characterized by a "spirit of... explained" in Isaiah 58:6-7, involving the release of the oppressed and the breaking of every yoke [3].
The tradition has long recognized the significance of Isaiah 58 in understanding Jesus' teaching on fasting. The cross-references between Isaiah 58 and Matthew 6 in various biblical commentaries and dictionaries attest to this connection [6, 7]. The critique of superficial fasting in both passages serves as a call to genuine piety and social justice.
Sources
- Isaiah “Isaiah 58:6 (Geneva1599) — Is not this the fasting, that I haue chosen, to loose the bandes of wickednes, to take off the heauie burdens, and to let the oppressed goe free, and that ye breake euery yoke?”
- Matthew “so that you are not seen by men to be fasting, but by your Father who is in secret, and your Father, who sees in secret, will reward you. -- Matthew 6:18”
- Torrey's Topical Textbook “Torrey's Topical Textbook: Fasting — Spirit of, explained -- Isa 58:6,7. Not to be made a subject of display -- Mt 6:16-18. Should be to God -- Zec 7:5; Mt 6:18. For the chastening of the soul -- Ps 69:10. For the humbling of the soul -- Ps 35:13. Observed on occasions of Judgments of God. -- Joe 1:14; 2:12. Public calamities. -- 2Sa 1:12. Afflictions of the Church. -- Lu 5:33-35. Afflictions of others. -- Ps 35:13; Da 6:18. Private afflictions. -- 2Sa 12:16. Approaching danger. -- Es 4:16. Ordination of ministers. -- Ac 13:3; 14:23. Accompanied by Prayer. -- Ezr 8:23; Da 9:3. Confession of si”
- Isaiah “Isaiah 58:3 (NASB) — 'Why have we fasted and You do not see? Why have we humbled ourselves and You do not notice?' Behold, on the day of your fast you find your desire, And drive hard all your workers.”
- Matthew ““Moreover when you fast, don’t be like the hypocrites, with sad faces. For they disfigure their faces, that they may be seen by men to be fasting. Most certainly I tell you, they have received their reward. -- Matthew 6:16”
- OpenBible.info “Cross-reference: Matt.6.9 → Isa.57.15 (confidence: 21 votes)”
- OpenBible.info “Cross-reference: Matt.5.3 → Isa.61.1 (confidence: 38 votes)”
- Easton's Bible Dictionary “Easton's Bible Dictionary: Fast — The sole fast required by the law of Moses was that of the great Day of Atonement (q.v.), Lev. 23:26-32. It is called "the fast" (Acts 27:9). The only other mention of a periodical fast in the Old Testament is in Zech. 7:1-7; 8:19, from which it appears that during their captivity the Jews observed four annual fasts. (1.) The fast of the fourth month, kept on the seventeenth day of Tammuz, the anniversary of the capture of Jerusalem by the Chaldeans; to commemorate also the incident recorded Ex. 32:19. (Comp. Jer. 52:6, 7.) (2.) The fast of the fifth month, ke”
- Smith's Bible Dictionary “Smith's Bible Dictionary: Fasts — + One fast only was appointed by the Mosaic law, that on the day of atonement. There is no mention of any other periodical fast in the Old Testament except in (Zechariah 7:1-7; 8:19) From these passages it appears that the Jews, during their captivity, observed four annual fasts,--in the fourth, fifth, seventh and tenth months. + Public fasts were occasionally proclaimed to express national humiliation and to supplicate divine favor. In the case of public danger the proclamation appears to have been accompanied with the blowing of trumpets. (Joel 2:1-15) (See ”
- Isaiah (Presbyterian) “Jamieson, Fausset & Brown on Isaiah 58 (introduction): REPROOF OF THE JEWS FOR THEIR DEPENDENCE ON MERE OUTWARD FORMS OF WORSHIP. (Isa 58:1-14) aloud--Hebrew, "with the throat," that is, with full voice, not merely from the lips (Sa1 1:13). Speak loud enough to arrest attention. my people--the Jews in Isaiah's time, and again in the time of our Lord, more zealous for externals than for inward holiness. ROSENMULLER thinks the reference to be to the Jews in the captivity practising their rites to gain God's favor and a release; and that hence, sacrifices are not mentioned, but only fasting an”
- CCEL (Reformed) “John Calvin, Institutes of the Christian Religion, section 94: 2:13 ); that is, to remind the people that fasting in itself is not of great value in the sight of God, unless accompanied with internal affection of the heart, true dissatisfaction with sin and with one’s self, true humiliation, and true grief, from the fear of God; nay, that fasting is useful 2465 for no other reason than because it is added to these as an inferior help. There is nothing which God more abominates than when men endeavour to cloak themselves by substituting signs and external appearance for integrity of heart. Acco”