Him that worketh. That is, hoping thereby to merit justification. Paul is drawing his illustration from everyday life. This verb was commonly used of working at a trade for a living (see Acts 18:3; 1 Cor. 9:6; 2 Thess. 3:12).
Reward. Gr. misthos, “pay,” “wages,” “earned reward” (see Matt. 20:8; James 5:4).
Reckoned. Gr. logizomai (see on v. 3). This word may be used of setting something to a person’s account that may or may not be his due. In this verse the workman’s wages are “reckoned,” or “counted,” to be his legal right. In v. 8, Paul speaks of not “imputing,” or “reckoning,” sin to the sinner.
Of grace. That is, as a gift (see on eh. 3:24).
Of debt. “The labourer is worthy of his hire” (Luke 10:7). If necessary he can claim it in a court of law. This represents the legalistic method of seeking salvation. If justification is a reward for works, we make God our debtor. Grace is not involved at all.