Appropriately the topic of this chapter follows that of the previous passage. For fasting was a kind of ritual mourning. From early times it was associated with bereavement, repentance, and prayer. The Law of Moses prescribed fasting only in connection with the Day of Atonement, but fasts were also proclaimed in times of national emergency. In later times the trauma which resulted from the destruction of Jerusalem and the temple in 587 BC gave rise to regular fast days to mark these terrible events.

The fast days were impressive, solemn occasions, when the whole community gathered. This was good in itself, but it was also dangerous, for it created an impression of piety which was often far removed from the real state of affairs. It imposed a uniformity of observance which disguised the difference between those who were genuine and those who were not (vv. 1-2). At its worst it could degenerate into self-righteousness. Religion that drifts into superstition and self-righteousness becomes a hollow thing, lacking integrity and power. This is the inevitable outcome when leaders fail to speak to God’s people about their sins and challenge them with on-going need for repentance. The command of verse 1 is an urgent one, which is still relevant today.

After the exposure of wrong fasting (vv. 1-5) comes a description of the kind of fasting that truly pleases God (vv. 6-12). It is fasting accompanied by genuine repentance, especially turning away from exploitation and quarrelling (vv. 3b, 4a, 6). It is not simply to go without food on the set fast days, but to adopt a lifestyle in which self-indulgence and greed are totally given up and replaced by generosity towards the poor (v. 7). This is the kind of fasting that pleases God and leads to His blessing being released (v. 9). The great paradox of the life of faith to which we are called is that blessing comes through self-denial, which we receive through giving, and that we gain our lives by laying them down. The only repentance that counts with God is the sort that can be seen in the way we live, especially in how we treat other people.

Conditions proved to be very difficult in Palestine after the return from exile. On the fast days the people cried out to God to hear them, and give them the good things He had promised (v. 3). The terms light, healing, righteousness and glory all refer to the same reality: full realization of covenant blessing for which they were longing (v. 8). But Isaiah here warns all who desire these good things, and even back up their petitions with fasting, that they cannot expect to be heard until they change the way they are living.

After this the closing exhortation to keep the Sabbath (vv. 13-14) seems like an anticlimax, until we remember the connection between the Sabbath and justice that was made back in 56:1-2. The exploitation of workers denounced in verse 3 may well have involved denying them rest that the Sabbath provided, and the idle words of verse 13 were perhaps glib rationalizations that justified such behavior. In any case, the call for true Sabbath observance, like the call for true fasting, is a call for a changed heart and life, not just the more meticulous observance of a ritual. There is no shortcut to joy and victory (v. 14); they come through repentance, and a willingness to live God’s way.

Isaiah 58:1-14 Reflection Questions:

Have you ever fasted? If so, what was the focus of your fast?

What is God seeing when He sees how you are living?

Are you willing to live God’s way? If so, what does that mean?