Deuteronomy 26:14 - Joseph Benson’s Commentary on the Old and New Testaments

I have not eaten thereof in my mourning This is thought by Spencer to have respect to some idolatrous custom then in use: such as that of the Egyptians, who, when they offered the first-fruits of the earth, were wont to invoke Isis with doleful lamentations. But, as the Israelites were not allowed to eat of things consecrated to God, when they were in a state of mourning, (Hosea 9:4,) this may probably be all that is here intended. Or the declaration may mean, I have not done it in sorrow, grieving that I was to give away so much of my profits to the poor, but I have cheerfully eaten and feasted with them, as I was commanded to do. For any unclean use As some of the old idolaters were wont to do, who separated part of the first-fruits for magical, and sometimes impure uses; or for any common use; for any other use than that which thou hast appointed; which would have been a pollution of them. Nor given aught thereof for the dead Or, to the dead; that is, says Spencer, to dead idols, such as the Gentiles worshipped, who offered their first-fruits to them, as if they had been the authors of their increase. But the expression, for the dead, more probably means for any funeral pomp or service, for, it seems, the Jews were wont to send in provisions to feast with the nearest relations of the party deceased; and in that case, both the guests and food were legally polluted, Numbers 19:11-14; and, therefore, to have used these tithes in such a way would have been a double fault, both a defiling of sacred food, and the employing of those provisions on sorrowful occasions, which, by God's express command, were to be eaten with rejoicing.