R’ Eli Munk wrote that these laws have been maintained from the time in the desert until now. He argued that none of the leaders of Judaism has considered the laws outmoded, and that this permanency is quite a unique phenomenon.
Various explanations have been given for the laws, such as an exercise in self-discipline, or a point of differentiation from other peoples, or that the forbidden foods are harmful to health. R’ Munk argued that the dietary laws have an absolute value, and that they sanctify our instinct for taking food. Elevating the flesh enables it to reach a state of harmony with the spirit, and the ritual laws pertaining to food give the Jewish home an air of sanctity. R’ Munk argued that the dietary laws have given Israel strength throughout its history, and the people learnt to be sober, prudent and moderate in their desires.
The dietary laws are classed as Chukim, non-rational laws, and give the people a challenge to attain the objective of holiness. R’ SR Hirsch explained that the search for food and the struggle for survival characterise all animals, but the animals excluded from the list have claws and rapidly digest their food. This leaves the clean animals, with cloven hooves and chewing the cud. The acceptable animals, birds and fish are listed. The chief characteristics of kosher birds are that they are neither birds of prey, nor scavengers.