Luke 10:2

2.The harvest is indeed abundant. I have explained this passage under the ninth chapter of Matthew; (32) but it was proper to insert it again in this place, because it is related for a different purpose. In order to stimulate his disciples the more powerfully to apply with diligence to their work, he declares that the harvest is abundant: and hence it follows, that their labor will not be fruitless, but that they will find, in abundance, opportunities of employment, and means of usefulness. He afterwards reminds them of dangers, contests, and annoyances, and bids them go and prepare themselves for traversing with speed the whole of Judea. (33) In short, he repeats the same injunctions which he had given to the Apostles; and, therefore, it would serve no good purpose to trouble the reader here with many words, since a full exposition of all these matters may be found in the passage already quoted. We may notice briefly, however, the meaning of that expression, salute no man by the way. It indicates extreme haste, when, on meeting a person in the way, we pass on without speaking to him, lest he should detain us even for a short time. Thus, when Elisha sent his servant to the Shunamite woman, he charged him not to salute any person whom he met:

if thou meet any man, salute him not;
and if any salute thee, answer not again, (2 Kings 4:31.)

Christ does not intend that his disciples shall be so unkind (34) as not to deign to salute persons whom they meet, but bids them hasten forward, so as to pass by every thing that would detain them.