John Calvin Reformed @genevareformer

Exodus 23:14. Three times shalt thou keep a feast. It is strange that Moses, who elsewhere enumerates several feast-days, should here only command them to appear in God’s presence thrice a year. Where then is the feast of trumpets and the day of atonement? for undoubtedly all were to be celebrated at Jerusalem.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The institution of the sabbatical year, Exo 23:10, Exo 23:11. Every seventh year the land was to rest; they must not plough nor sow it at the beginning of the year, and then they could not expect any great harvest at the end of the year: but what the earth did produce of itself should be eaten from hand to mouth, and not laid up.

Commenting on Exodus 23:10-19

John Gill Reformed Baptist @doctorgill

And the feast of harvest,.... This is the second feast, the feast of wheat harvest, between which and barley harvest were fifty days; or between the firstfruits of the one and the first fruits of the other were seven weeks, as Aben Ezra observes, and was sometimes called the feast of weeks; at which feast were to be brought: the first fruits of thy labours...