"Cast out" (garash?) versus "Give place/enlarge/swell" (rachab?)
These poor Zoramites had been cast out...a detail that is mentioned in verse 2, verse 5 (twice), verse 9, verse 12 (twice), and verse 24 -- a total of 7 times.
Then Alma proceeds to teach them about the word of God, likening it to a seed. He cautions them not to "cast it out" by their unbelief. Same words...coincidence? Maybe not.
I'm not a Hebrew expert by any means, but I try to learn what I can according to my understanding. The root "garash" can refer to casting out or driving out, so it seems to fit both contexts (the status of the poor Zoramites and what we should not do it the word of God). This root also has definite covenant connections, which I'll demonstrate below.
After that, Alma invites the people (twice) to "give place" in their hearts for the seed to grow (see verse 27 and 28). When they do, he tells them it will "swell within [their] breasts" and "enlarge [their] soul."
One particular Hebrew root "rachab" seems to fit all three of these contexts. This root also has very clear covenant connotations.
I'll outline two Old Testament examples of how these roots are used in conjunction with covenants, and you can decide for yourself if you believe Alma or Mormon is making intentional references to covenant language:
Genesis 26 -- "rachab"
In Genesis 26, Isaac is having trouble with his neighbors, who envy his wealth. He digs a well but they fight with him over it, so he names it "Argue." He digs another well and they fight again with him, so he names that well "Fight." The third well is all his -- no one else makes a claim on it, so he names it Rehoboth ("Room enough"), and declares that the Lord has "given us room" (using the root "rachab"). He is convinced they "will flourish in the land."
Later that night:
In this example, just after the Lord "gave him room," a covenant was made. This is one on several examples of how the root "rachab" is associated with covenant-making.
Exodus 34 -- "garash" and "rachab"
Here is another example where both "garash" and "rachab" show up in the context of covenant-making:
Then the said: “I am making a covenant with you. Before all your people I will do wonders never before done in any nation in all the world. The people you live among will see how awesome is the work that I, the , will do for you....I will drive out (garash) before you the Amorites...I will drive out (yarash -- related to "garash") nations before you and enlarge (rachab) your territory... (Exodus 34, NIV, roots from BibleHub)
The Lord commands His people to "drive out" the unbelievers in the land in order to "enlarge" their territory.
We have to remember that the seed is not faith, it is the word of God. The word of God is not just the scriptures, it is embracing the entirety of the Gospel, complete with the covenants associated with priesthood ordinances. Thus, Alma-2 is not only teaching the poor Zoramites how to have faith, I believe he is channelling specific covenant language from the Old Testament to teach them about "casting out" their unbelief to "make room" for the word of God to enlarge their hearts and bring them everlasting joy.