Many of the Israelites were relying on their practice of the Mosaic rites to satisfy God. The true meaning of the rites had not affected their lives. God intended the system of worship He prescribed to illustrate the importance of heart relationship with Himself that should affect interpersonal relationships. This pericope exposes the superficial attitude of many of God's people with strong irony.
58:1 The transgressions and sins that the Lord called Isaiah to proclaim to His people were so serious that the prophet needed to grab their attention with loud announcements. The name "the house of Jacob"calls attention to the Jacob-like quality of the nation that God would expose, namely, the people's attempts to manipulate God.
58:2 Even though the Israelites sinned, they sought the Lord constantly and inquired concerning His ways. They claimed to be a righteous people who had observed the Mosaic Law carefully. They asked God for justice, and they delighted in the thought that He was near them.
58:3 They could not understand why God had not blessed them because they had fasted and humbled themselves (cf. Mal. 3:13-15).659The reason God had not blessed them was that they fasted but did not demonstrate the attitudes and activities that fasting represented. They did not really sacrifice their own desires, and they continued to treat other people inconsiderately. They pursued their personal interests and worked when they fasted, and they insisted that their employees keep on working. They were practicing religious ritual to try to manipulate God into blessing them.
"But repentance is not for the purpose of getting God to do anything; it is an expression of the conviction that my ways are wrong and God's ways are right, whether he does anything for me or not."660
58:4 The spiritually insensitive Israelites did not consciously fast so they could be contentious and strive and beat each other up, but these were the results of their fasts. Fasting made them grouchy and belligerent, and they took these sinful feelings out on their neighbors. It would have been better for their neighbors if they had not fasted at all. These religious hypocrites were really fasting for reasons other than mourning over their sinfulness.
58:5 This was not the type of fasting God approved (cf. 1:11; Ps. 51:16-17; Luke 18:9-14). It consisted only in His people bowing their heads, not their hearts. Bowing the head like a reed expresses formal worship, like a reed automatically and unthinkingly bending in response to wind. The people sat in sackcloth and ashes, but they did not really mourn over their disobedience to the Lord. They thought their outward fasting, bowing, dressing, and adorning were more important than their attitudes and behavior, though they probably did not realize it and certainly did not admit it (cf. James 1:27; 4:8).
