Matthew Poole and continuators on Leviticus 25:21

21 Then I will command my blessing upon you in the sixth year, and it shall bring forth fruit for three years.

Not compleatly, but in great part, to wit, for that part of the sixth year which was between the beginning of harvest and the beginning of the seventh year, for the whole seventh year, and for that part of the eighth year which was before the harvest, which reached almost until the beginning of the ninth year. And by this expression we may understand the meaning of that eminent passage of Christs being three days and three nights in the grave, to wit, one whole day and part of two days: Of which more, if God please, in its proper place. This is added to shew the equity of this command. As God would hereby try their Faith and exercise Obedience, so he gave them an eminent proof of his own exact providence and tender care over them in making provisions suitable to their necessities. Albeit it be also probable, that divers of them, especially such as were more solicitous or distrustful of Gods providence, did lay up something of the fruits of former years against this time.

Marginal references: (i. e.) Give. Commanding is oft used in Scripture either for the performance of promised blessings, as Deut. 28. 8. Psal. 111. 9. and 133. 3. or for the execution of threatned judgements, as Isa. 5. 6. Amos. 9. 4. both being acts of Gods providential will as the command is of his legislative will.