What does Psalm 73:21 mean?

Asaph began this psalm expressing his envy and angst over the existence of wicked, prosperous people (Psalm 73:1–3). He came to realize the error of his attitude when he more carefully considered God's truth (Psalm 73:15–17). Here, he confesses that some of his error was in bitterness, which is closely related to envy. Pain and anxiety come in many forms, but when we are sour at the thought that we "should" be experiencing something else, that's bitterness.

Looking at various English translations of this verse helps to capture the depth of emotion which Asaph experienced. A key phrase is rendered as "pricked in heart" (ESV), "pierced within" (NASB), "innermost being was wounded" (CSB), or "heart was grieved" (NIV).

Believers today may harbor bad attitudes until they are convicted by the Holy Spirit, and such temptations are natural (1 Corinthians 10:13). It is important to respond positively to the Spirit's convicting ministry and not grieve or quench Him (Ephesians 4:30; 1 Thessalonians 5:19). The proper course of action to take when convicted is to confess the sin earnestly and sincerely and determine by God's grace not to repeat it. First John 1:9 promises: "If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness." It would be wrong to misinterpret the meaning of the Holy Spirit's convicting ministry. The conviction does not mean we no longer belong to God because we have sinned; instead, it is evidence that we do belong to Him.

Asaph, in that same way, was able to bring his complaint to God, work through his own weakness into God's strength, and come back to a greater trust in what was true.