Note to As You Like It, 3.5.91: "covetousness"
covetousness: Apparently Phebe's little joke is that she already belongs to the "neighbour" of Silvius (i.e., the beautiful young man who Rosalind pretends to be), and so Silvius' desire for her is "covetousness." The Bible says, "Thou shalt not covet thy neighbour's house, thou shalt not covet thy neighbour's wife, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor any thing that is thy neighbour's" (Exodus 20:17, KJV).
Silvius and Phoebe
by John Pettie, 1872