Leviticus 16:1-4, 11-14:  And the LORD spake unto Moses after the death of the two sons of Aaron, when they offered before the LORD, and died; And the LORD said unto Moses, Speak unto Aaron thy brother, that he come not at all times into the holy place within the vail before the mercy seat, which is upon the ark; that he die not: for I will appear in the cloud upon the mercy seat. Thus shall Aaron come into the holy place: with a young bullock for a sin offering, and a ram for a burnt offering. He shall put on the holy linen coat, and he shall have the linen breeches upon his flesh, and shall be girded with a linen girdle, and with the linen mitre shall he be attired: these are holy garments; therefore shall he wash his flesh in water, and so put them on. And Aaron shall bring the bullock of the sin offering, which is for himself, and shall make an atonement for himself, and for his house, and shall kill the bullock of the sin offering which is for himself: And he shall take a censer full of burning coals of fire from off the altar before the LORD, and his hands full of sweet incense beaten small, and bring it within the vail: And he shall put the incense upon the fire before the LORD, that the cloud of the incense may cover the mercy seat that is upon the testimony, that he die not: 14And he shall take of the blood of the bullock, and sprinkle it with his finger upon the mercy seat eastward; and before the mercy seat shall he sprinkle of the blood with his finger seven times.

This Gem is a pearl.  Pearls are known for a very unique quality.  At the core of their beauty, their value, their worth, is a grain of worthless sand.  That grain of sand is transformed into a pearl through no effort of its own.  This transformation is performed by another being, an oyster.  As a grain of sand it is inherently irritating to its host, but it has no ability to change that fact.  However, once it has been transformed by the oyster, it can remain in the oyster's presence without causing it additional irritation.

This Bible Gem is one of three that put into view Heavenly Father's plans concerning the Day of Atonement.  Each of these three Gems is a pearl because each portrays a transformation which makes a pearl out of a grain of sand.  Each Gem exhibits something magnificent transformed out of something inherently "irritating".

First the Holy Spirit sees fit to remind the observer of the deaths of Aaron's two oldest sons.  These men were priests who presented themselves before the Lord in a way that was not according to his instructions.  They were immediately killed by fire that came out from the presence of the LORD Leviticus 10:1-2.  The stark reminder of this tragic event ensured Moses, Aaron, and all the priests that followed over the years would pay close attention to the instructions Heavenly Father was about to present concerning the Day of Atonement.

Before Aaron could go behind the veil and enter the holy place (usually called the Most Holy Place or the Holy of Holies) he had to be transformed.  Even though he was Israel's High Priest he was inherently unfit to come into the room where the presence of Heavenly Father resided as a cloud upon the mercy seat.  The transformation of the High Priest required a sin offering, an atonement offering for Aaron's sins.  Aaron's sin had to be removed before he would be acceptable to his Lord.  This was something he could not do himself.  The price for his sin was too high.  Another being, a substitute represented here by a young bull, had to do it for him.  But blood still had to be spilt and death still had to occur.  In this way the penalty for Aaron's sin would be paid.  And Aaron, inherently contaminated by sin, would be acceptable to God - because the guilt of his sin was removed by this substitute.