has remained
This phrase indicates a deliberate choice or necessity for Erastus to stay in Corinth. The Greek word used here, "emeinen," suggests a sense of abiding or continuing in a place. It reflects the strategic importance of Corinth as a hub for early Christian mission work. Erastus's presence there could imply his ongoing commitment to the church's growth and stability in a city known for its diverse and often challenging cultural environment.

at Corinth
Corinth was a major city in ancient Greece, known for its wealth, commerce, and moral challenges. It was a place where Paul had previously established a church, as seen in his letters to the Corinthians. The city's strategic location made it a vital center for the dissemination of the Gospel. The mention of Corinth here underscores the importance of maintaining a Christian witness in influential urban centers, despite the challenges they may present.

and Trophimus
Trophimus was a companion of Paul, mentioned in Acts 20:4 and Acts 21:29. His presence with Paul on his journeys indicates his dedication to the mission of spreading the Gospel. Trophimus's role as a Gentile believer also highlights the inclusive nature of the early Christian movement, breaking down ethnic and cultural barriers in the body of Christ.

I left sick
This phrase reveals the human side of Paul's ministry. Despite his apostolic authority and the miracles associated with his ministry, Paul acknowledges the reality of illness and human frailty. The Greek word "asthenounta" conveys weakness or infirmity, reminding us that even the most faithful servants of God are not immune to suffering. This acknowledgment can be a source of comfort, as it shows that God’s power is made perfect in weakness (2 Corinthians 12:9).

in Miletus
Miletus was an ancient city on the western coast of Asia Minor, near Ephesus. It was a place where Paul had previously met with the Ephesian elders (Acts 20:17-38). The mention of Miletus here suggests a strategic decision by Paul, possibly due to the city's location or the presence of a supportive Christian community. It also reflects the itinerant nature of Paul's ministry, constantly moving to spread the Gospel and strengthen the churches.

Another "Eastus" appears among those who ministered to St. Paul at Ephesus (Acts 19:22). Him St. Paul sent on missionary work into Macedonia. There were, therefore, among St. Paul's friends two men of this name: the one a resident official personage at Corinth; the other one of that band who journeyed hither and thither for the propagation of the faith.

But Trophimus have I left at Miletum sick.--Trophimus, a Gentile Christian, who was with St. Paul on his third missionary journey, and whom the Apostle was accused of taking into the Temple at Jerusalem. It was this accusation on the part of the Jews which led to St. Paul's arrest which preceded his first long imprisonment. The event here alluded to must have taken place some time after the Apostle's release from the first imprisonment, A.D. 63, and, probably, in the course of his last journey, shortly before his second arrest and imprisonment at Rome, about A.D. 66.

Miletus (not "Miletum"), a seaport of Caria, about thirty miles from Ephesus, once a city of great renown, whence, it is said, eighty colonies had proceeded; but in the days of St. Paul its glories were already on the wane. It is now famous only for its vast ruined theatre. (See Acts 20:15.)

It has been suggested that this mention of Trophimus was intended to clear him of any neglect. "Erastus," wrote the Apostle, "remained at Corinth; but Trophimus' reason for not coming to Rome was his sickness."