Leviticus 7:15 - Joseph Benson’s Commentary on the Old and New Testaments

The flesh shall be eaten the same day This was partly that none of it might be exposed to corruption, (for by the third day it might easily, in those hot countries, putrefy,) and partly that the offerer might not be sordidly saving of this sacred banquet, but be taught to show his piety to God by his love to his fellow-creatures, forthwith inviting his friends to partake of it with him; and in case he and they could not eat it up, by distributing the remains among the poor. This law might also be intended to prevent their spending many days in feasting under the pretence of religion. It may be observed further here, that the longest time allowed for eating the flesh of any of the sacrifices enjoined by Moses, was the day after that on which they were killed; the eating of it on the third day is declared to be an abomination.