Behold, I will corrupt your seed, and spread dung upon your faces, even the dung of your solemn feasts; and one shall take you away with it. Behold, I will corrupt your seed - So as to render it unfruitful. Newcome translates, - "I will take away from you the shoulder." This was the part that belonged to the priest, Leviticus 7:32; Deuteronomy 18:3.
Spread dung upon your faces - Instead of receiving a sacrifice at your hands, I will throw your offerings back into your faces. Here God shows his contempt for them and their offerings.