The symbolism in Alma 46

When Nephite dissenters wanted to destroy their liberty in Alma 46, Moroni rent his coat (v.12), an Israelite sign of great anguish.

And it came to pass that he rent his coat; and he took a piece thereof, and wrote upon it

In response, all Nephites who supported the cause of freedom rent their garments too (v.21). Moroni then makes the connection to Joseph of Egypt because

• The Nephites are his descendents (remnant of his seed)
• His coat was rent like that of the Nephites
• His brothers were his enemies, just like the Amalickiahites were the brothers and enemies of the Nephites
• His brothers wanted to slay him, ended up selling him and he was cast into prison in Egypt (note Moroni's wording at the end of verse 23)

23 Moroni said unto them: Behold, we are a remnant of the seed of Jacob; yea, we are a remnant of the seed of Joseph, whose coat was rent by his brethren into many pieces; yea, and now behold, let us remember to keep the commandments of God, or our garments shall be rent by our brethren, and we be cast into prison, or be sold, or be slain.

24 Yea, let us preserve our liberty as a remnant of Joseph; yea, let us remember the words of Jacob, before his death, for behold, he saw that a part of the remnant of the coat of Joseph was preserved and had not decayed. And he said—Even as this remnant of garment of my son hath been preserved, so shall a remnant of the seed of my son be preserved by the hand of God, and be taken unto himself, while the remainder of the seed of Joseph shall perish, even as the remnant of his garment.

25 Now behold, this giveth my soul sorrow; nevertheless, my soul hath joy in my son, because of that part of his seed which shall be taken unto God.

26 Now behold, this was the language of Jacob.

27 And now who knoweth but what the remnant of the seed of Joseph, which shall perish as his garment, are those who have dissented from us? Yea, and even it shall be ourselves if we do not stand fast in the faith of Christ.

There is a lot of neat symbolism here

1. Rending their garments was a token. Even as they had rent their garments, so they would be rent if they fell into transgression
2. The Nephites were a remnant of Joseph and a preserved piece of his rent coat serves as a symbol of the Nephites in the Americas who were his descendants
3. Moroni took a 'remnant' of his torn coat and used it as the title of liberty. This is a symbol of the preserved piece of Joseph's coat or the Nephites. Moroni reminded them that they as this remnant needed to stay faithful in order to be preserved like Joseph had been preserved

It's also interesting that the italic part is a quote by Jacob, Joseph's father from the brass plates, which we don't have in the Bible.