(20) And your strength shall be spent in vain.--That is, with the heaven over them as metal, their labour expended in ploughing, digging, and sowing will be perfectly useless.

Your land shall not yield her increase, as no amount of human labour will make up for the want of rain. In Deuteronomy 11:17, where the same punishment is threatened, and the same phrase is used, the Authorised Version unnecessarily obliterates the identity of the words in the original by rendering them "the land yield not her fruit."

26:14-39 After God has set the blessing before them which would make them a happy people if they would be obedient, he here sets the curse before them, the evils which would make them miserable, if they were disobedient. Two things would bring ruin. 1. A contempt of God's commandments. They that reject the precept, will come at last to renounce the covenant. 2. A contempt of his corrections. If they will not learn obedience by the things they suffer, God himself would be against them; and this is the root and cause of all their misery. And also, The whole creation would be at war with them. All God's sore judgments would be sent against them. The threatenings here are very particular, they were prophecies, and He that foresaw all their rebellions, knew they would prove so. TEMPORAL judgments are threatened. Those who will not be parted from their sins by the commands of God, shall be parted from them by judgments. Those wedded to their lusts, will have enough of them. SPIRITUAL judgments are threatened, which should seize the mind. They should find no acceptance with God. A guilty conscience would be their continual terror. It is righteous with God to leave those to despair of pardon, who presume to sin; and it is owing to free grace, if we are not left to pine away in the iniquity we were born in, and have lived in.And your strength shall be spent in vain,.... In endeavouring to till the ground, to plough, or sow, or to dig about the vines or olives, and prune them:

for your land shall not yield its increase; produce corn, and bring forth grass, the one for the use of men, the other for the use of the cattle, and therefore both must starve:

neither shall the trees of the land yield their fruits; such as vines, olives, figs, pomegranates, &c. which were very plentiful in the land of Judea, and on which they much lived, and on which their more comfortable subsistence at least depended, see Habakkuk 3:17; all this is the reverse of Leviticus 26:4.