Gezera Shawa is a Hebraism in which two seemingly unrelated passages of scripture are brought together because they share a common word.
Matthew L. Bowen explains that
The Book of Mormon contains several quotations from the Hebrew Bible that have been juxtaposed on the basis of shared words or phrases, this for the purpose of interpreting the cited scriptural passages in light of one another.– Matthew L. Bowen – Onomastic Wordplay on Joseph and Benjamin and Gezera Shawa in the Book of Mormon
One example is found in 2 Nephi 25:17 in which Nephi brings together two scriptures from the Old Testament that share a common word. What is impressive about this example is that the common word is not the same in English, it can only be seen in Hebrew.
And the Lord will set his hand again the second time to restore his people from their lost and fallen state. Wherefore, he will proceed to do a marvelous work and a wonder among the children of men.
In this instance Isaiah 11:11 and Isaiah 29:14 are quoted from the Old Testament together which share the common word “yosip” which means both “again” and “proceed”.
Why would Joseph Smith have brought these two scriptures together if he didn’t understand the underlying Hebrew?