Albert Barnes Commentary Deuteronomy 26:14

"I have not eaten thereof in my mourning, neither have I put away thereof, being unclean, nor given thereof for the dead: I have hearkened to the voice of Jehovah my God; I have done according to all that thou hast commanded me." — Deuteronomy 26:14 (ASV)

I have not eaten thereof in my mourning - when the Israelite would be unclean (compare the marginal references).

Nor given ought thereof for the dead - The reference is not so much to the superstitious custom of placing food on or in tombs as to funeral expenses, and more especially the usual feast for the mourners (Ezekiel 24:17; Hosea 9:4). Dedicated things were to be used for glad and holy feasting. Therefore, they were not for funeral banquets, because death and all associated with it was regarded as unclean.