John Calvin on Luke 6:1-7

Luke 6:1. On the second-first Sabbath It is beyond all question that this Sabbath belonged to some one of the festival-days which the Law enjoined to be observed once every year. Some have thought that there were two festival-days in immediate succession; but as the Jews had arranged their festival-days after the Babylonish captivity so that one day always intervened between them, that opinion is set aside. Others maintain with greater probability, that it was the last day of the solemnity, which was as numerously attended as the first. I am more inclined to favor those who understand by it the second festivity in the year; and this agrees exceedingly well with the name given to it, the second-first Sabbath, because, among the great Sabbaths which were annually observed, it was the second in the order of time. Now the first was the Passover, and it is therefore probable that this was the feast of first-fruits, (Exodus 23:15, 16.)