This verse is a parenthetical comment on the reception of divine grace (v. 1). It constitutes an urgent appeal to men to seek reconciliation with God lest they receive the grace of God in vain. The quotation is from the LXX of Isa. 49:8 (see comment there). Isaiah looks forward to the “day of salvation” as the time of the Messiah. Paul here recognizes that the prophecy has been fulfilled in Christ. The first advent of Christ ushered in an era that is favorable to salvation (see DA 37). So long as Christ intercedes for sinners the “day of salvation” will continue.

That is, helped.

 That is, a time when repentant sinners will be received (see on Isa. 49:8).

 That is, the time during which the light of probation lingers (see John 12:35). Eventually the day of mercy will close, and when it does there will be no second chance for those who have spurned God’s grace. Men often procrastinate because they think the day of salvation will continue indefinitely, that temporal matters require first consideration, that pleasure must be pursued, that it will be easier to repent and believe tomorrow than it is today. They forget that the only time man has for salvation and for victory over any sin is the present moment, and that victory postponed becomes defeat. Delay is both foolish and dangerous. Life may be cut short; deterioration of mind and body may make attention to spiritual things difficult or impossible. The heart may be fatally hardened and the desire for salvation lost; the Holy Spirit may cease to strive. Procrastination is ultimately equivalent to rejection.