Kidneys of wheat
In Proteus Stephen thinks of priests "moving burly in their albs, tonsured and oiled and gelded, fat with the fat of kidneys of wheat." The last phrase alludes to a passage in the Bible, but its effect is to satirize the hypocrisy of priests, eating well while they promote poverty among their parishioners. The image of burly, fat, oily priests coheres with a strain of anti-clericalism that runs through Joyce's works.
In Deuteronomy, Moses sings of the blessings that God bestowed on Jacob and his people Israel: "He made him ride on the high places of the earth, that he might eat the increase of the fields; and he made him to suck honey out of the rock, and oil out of the flinty rock; Butter of kine, and milk of sheep, with fat of lambs, and rams of the breed of Bashan, and goats, with the fat of kidneys of wheat; and thou didst drink the pure blood of the grape" (32:13-14). Thornton credits Ulrich Schneider with having first spotted the biblical allusion in Proteus.
In the Christmas dinner scene of A Portrait of the Artist, Mr. Casey speaks scornfully of the "Princes of the church," and Simon Dedalus chips in with a caricature of Michael Logue, at the time the archbishop of Armagh and Primate of All Ireland (he was made a cardinal in 1893): "—Tub of guts, said Mr Dedalus coarsely. He has a handsome face, mind you, in repose. You should see that fellow lapping up his bacon and cabbage of a cold winter's day. O Johnny! / He twisted his features into a grimace of heavy bestiality and made a lapping noise with his lips."
Leopold Bloom has similar thoughts in Lestrygonians, when he sees one of Dedalus' countless daughters: "Fifteen children he had. Birth every year almost. That's in their theology or the priest won't give the poor woman the confession, the absolution. Increase and multiply. Did you ever hear such an idea? Eat you out of house and home. No families themselves to feed. Living on the fat of the land. Their butteries and larders. I'd like to see them do the black fast Yom Kippur. Crossbuns. One meal and a collation for fear he'd collapse on the altar."
In Oxen of the Sun kidneys of wheat, with the aid of yeast, make the mash that produces ale: "it was a marvel to see in that castle how by magic they make a compost out of fecund wheatkidneys out of Chaldee that by aid of certain angry spirits that they do into it swells up wondrously like to a vast mountain."