Albert Barnes Commentary Acts 20:31

"Wherefore watch ye, remembering that by the space of three years I ceased not to admonish every one night and day with tears." — Acts 20:31 (ASV)

Therefore watch (Matthew 24:42). In view of the dangers that threaten you (Acts 20:28), the danger from men not connected with the church (Acts 20:29), and the danger that will arise from the lovers of power among yourselves (Acts 20:30), be on your guard. Observe the approach of danger, and oppose it.

Remember. Recall my advice and admonitions regarding these dangers.

By the space of three years. In Acts 19:10, we are told that Paul spent two years in the school of Tyrannus. In Acts 19:8, it is said that he was teaching in the synagogue at Ephesus for three months. In addition to this, it is likely that he spent some more months in Ephesus instructing the church in other places. Perhaps, however, by the phrase 'three years,' he meant to use merely a round number, denoting about three years; or, according to Jewish customs, part of each of the three years—one whole year, and a considerable portion of the other two. (See Barnes on Matthew 12:40).

I ceased not. I continued to do it.

To warn. To admonish; to place before the mind, nouyetwn; setting the danger and duty of each individual before them.

Every one. He had thus set them an example of what he had instructed (Acts 20:28). He had admonished each individual, whatever their rank or standing. It is good when a minister can refer to his own example as an illustration of what he meant by his teachings.

Night and day. Continually; at every opportunity.

With tears. Showing his deep feeling and his deep interest in their well-being. (See Barnes on Acts 20:19).