Meilah is translated either as “sacrilege” or “trespass.” It refers to one who unwittingly makes prohibited use of property that belongs to the Temple. The subject is dealt with in Leviticus 5:15-16:
When a person commits trespass, being unwittingly remiss about any of the Lord’s sacred things, he shall bring as his penalty to the Lord a ram without blemish from the flock, convertible into payment in silver by the sanctuary weight, as an asham (guilt offering). He make restitution for that wherein he was remiss about the sacred things, and he shall add a fifth part to it and give it to the priest. The priest shall make expiation on his behalf with the ram of the guilt offering, and he shall be forgiven.
As we can see from these verses when a person commits sacrilege he must do three things: 1) bring an asham; 2) make restitution for the amount he benefited; 3) add an extra fifth. The restitution and the added fifth are given to the Temple in place of that which he benefited. One who intentionally trespasses pays back only the principle. He does not pay back an extra fifth nor does he bring a sacrifice. There is a debate about his punishment: according to Rabbi he gets “death by the hands of heaven” whereas the other rabbis hold that he receives lashes. With that brief introduction, we are on our merry way. Good luck!