Ananias wanted Saul to respond right away. God had chosen him, Jesus had appeared to him, and there was nothing left to wait for. Barnes reads the question as "Why dost thou delay, or wait any longer?" Matthew Henry draws the lesson: "Our covenanting with God in Christ is needful work, that must not be deferred." The question is warm, not harsh. It calls a new believer to step forward.

In his speech Paul does not stop to describe his baptism; he moves on to his return to Jerusalem (Acts 22:17). Luke's earlier account records what happened: Saul "received sight forthwith, and arose, and was baptized" (Acts 9:18). Soon after, "straightway he preached Christ in the synagogues, that he is the Son of God" (Acts 9:20).

The Greek for "why tarriest thou" uses the verb mello, here "to delay." The commands that follow, "be baptized" and "wash away," are both in the middle voice. "Calling on" (epikalesamenos) describes the act that goes with them.

Commentators are careful about "wash away thy sins." Barnes says to "Receive baptism as emblematic of the washing away of sins," and adds, "It cannot be intended that the external rite of baptism was sufficient to make the soul pure." Gill says it is "not that it is in the power of man to cleanse himself from his sins," but baptism may be "a means of leading the faith of God's children to the blood of Christ." Barnes links "calling on the name of the Lord" to prayer "For pardon and sanctification" (Romans 10:13).

Ananias' question shows how fully God welcomes a former enemy. Saul had come to Damascus to bind "all that call on thy name" (Acts 9:14). Now Ananias tells him to be baptized, "calling on the name of the Lord" himself (Acts 22:16). The persecutor becomes one of those who call on the name.

There is no waiting period in Ananias' words, no list of things Saul must first prove. Grace had already reached him. Matthew Henry sums up the promise as "Receive the comfort of the pardon of thy sins." The only right response was to receive it.