The adverb Immediately is in focus here as it is in verse 22. It represents a form of the adverb which is favored by Matthew, who uses it twelve times (see 8.3; 13.5; 14.22, 31; 20.34; 24.29; 25.16; 26.49, 74; 27.48), as compared to six times by Luke, three times by John, and none by Mark. It should be translated “At once,” “Right away,” or “Without delay.”

They left their nets, that is, “they left their nets right there,” “they abandoned their nets,” or “they quit working with their nets.”

The Greek expression translated followed is different from the verb used in verse 19 but has the same meaning in this context. As used in the New Testament, it frequently has the extended meaning of “follow as a disciple.” A good example of this shift may be observed in John 1.37-38, where the literal meaning of “follow” is intended. But in verses 40 and 43 of that same chapter the extended sense of “be a disciple” comes into focus.

Followed here may well be translated “they became his disciples (or, followers)” or “they … went with him,” as in Good News Translation.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .