Yehezkiel 4:12

4:12 And you must eat the food like you would a barley cake. You must bake it in front of them over a fire made with dried human excrement.” ¹ 

Yehezkiel 4:15

4:15 So he said to me, “All right then, I will substitute cow’s manure instead of human excrement. You will cook your food over it.”

[4:12]  ¹ sn Human waste was to remain outside the camp of the Israelites according to Deut 23:15.