The Egyptian Book of the dead by P. Le Page Renouf and Edouard Naville

5. See Herodotus, II, 47, without attaching too much importance to

details. The pig was certainly not considered impure (μιαρός) in the days of the third or fourth dynasty, when Amten, who had risen to the highest dignities, enumerates swine among the domestic animals it is natural to possess. And impure animals were not offered in sacrifice. But long before the days of Herodotus a change had taken place in the Egyptian religion as to the nature of Sutu. Plutarch and Aelian are to be read with the like caution. Some of their information is correct, but it is mixed up with much error.