Wow, this chapter is small but is packed with stuff. And I only understood part of it. I wish I had kept my Book of Mormon Student manual from college!
In this chapter, Isaiah has an experience in which he learns that his sins are forgiven. We read about other prophets in the scriptures who have similar experiences (Enos, Alma the Younger, Joseph Smith), but this particular imagery is unique. Isaiah sees a heavenly seraph. The Bible Dictionary says this:
"Seraphim: Probably fiery beings.
Angelic beings mentioned in the account of Isaiah’s vision (Isa. 6: 2). They are represented as winged and partly human in form. They are attendants in Jehovah’s court, the ministers of the heavenly sanctuary, joining in adoration before the throne."
This heavenly being puts a hot coal on Isaiah's lips, which purges his sins. The image of that used to scare me as a kid, because I imagined his mouth getting burned. But I think that imagery now is actually pretty powerful to me--his sins were burned away. We all know that becoming clean and pure is sometimes more like a fiery ordeal than a peaceful cleansing!
In my scriptures, I wrote a few notes next to this chapter. I don't know if these were my own thoughts or from a lesson, though I suspect the latter. The notes liken the seraph and the coal unto the priesthood blessing and passing the sacrament. I like that thought--we have already had our sins washed away through baptism! And every week we have the opportunity to renew that covenant and become clean again when we partake of the sacrament.
Those are just a few thought. Have a great day!