First Nephi appealed to Moses who testified of the coming of the Son of God and then said,
16 And now behold, Moses did not only testify of these things, but also all the holy prophets, from his days even to the days of Abraham.
17 Yea, and behold, Abraham saw of his coming, and was filled with gladness and did rejoice.
18 Yea, and behold I say unto you, that Abraham not only knew of these things, but there were many before the days of Abraham who were called by the order of God; yea, even after the order of his Son; and this that it should be shown unto the people, a great many thousand years before his coming, that even redemption should come unto them. (Helaman 8:16-18)Then Nephi lists a number of other prophets who also testified of the coming of the Son of God including, Zenos, Zenock, Isaiah, Jeremiah, and Ezias. Of this list Isaiah and Jeremiah are well known biblical prophets but the other three are apparently unknown prophets from biblical times. Both Zenos and Zenock are mentioned in other parts of the Book of Mormon and in a few cases are even quoted at length. But for Ezias this is his only mention. So other than having his name included in a list of prophets who testified of the Son of God, nothing else known about him, other than the oh so helpful footnote of "TG Scriptures, Lost".
If we do a search of the Bible for Ezias we come up with nothing. But if we extend our search a little we find this [biblestudytools.com]:
EZIAS
e-zi'-as:
the Revised Version (British and American)
OZIAS (which see).If we look up the entry for Ozias we find:
OZIAS
o-zi'-as:
(1) (Ozeias, Ozias, Codex Vaticanus a b): The son of Micah, a Simeonite, one of the 3 rulers of Bethulia in the days of Judith (Judith 6:15,16; 7:23; 8:9; 10:6).
(2) (Ozeias, Codex Vaticanus and Swete; the King James Version has Ezias (1 Esdras 8:2), following Codex Alexandrinus Ezias): An ancestor of Ezra (1 Esdras 8:2; 2 Esdras 1:2) equals "Uzzi" of Ezra 7:4; 1 Chronicles 6:51.
(3) Head of a family of temple-servants who returned with Zerubbabel (1 Esdras 5:31) equals "Uzza" of Ezra 2:49; Nehemiah 7:51.
(4) Greek form of UZZIAH (which see) in Matthew 1:8,9 the King James Version. A king of Judah.So it turns out that Ezias is a Hebrew name and is found in the Bible. It's just that there are several different ways of writing the original Hebrew name in English. It is also interesting to note that the version of the name, "Ezias", that we are concerned with does appear in the King James Version of the Bible, but only in the Apocrypha (the book of 1 Esdras). But most Protestant (and all LDS) versions of the Bible exclude the Apocrypha, so I did not immediately think including the Apocrypha in my search, but it is good that it came up. There are variations in the way the names are written in English but they all go back to the same Hebrew root name, עֻזִּי (`ZYH), which means "strong".
So now we have a reference point and names and people to investigate as possibilities. Before we started this investigation we knew nothing about Ezias other than we was supposedly a Biblical prophet, who is not found in the Bible. But now we have some indication that the name Ezias is a Hebrew name, and that there are a few candidates for who he might be in the Bible. Let us consider the four candidates mention by the "International Standard Bible Encyclopedia", as given above (Orr, James, M.A., D.D. General Editor. "Entry for 'OZIAS'". "International Standard Bible Encyclopedia". 1915.).
The first, Ozias, a ruler of the city Bethulia in the days of Judith. Not much known about him, maybe not a good candidate. The second is a ancestor of Ezra, and a direct descendant of Aaron, and therefore a High Priest. Perhaps a good candidate. The third is someone who lived after the Jews came back after the Babylonian captivity, so that rules him out. The forth was a king of Judah who died from leprosy. Not perhaps the best candidate. [Author note after some more exploring: "Uzzi" is listed (#6) as one of the recognized high priests over the tabernacle. There are more people of the same name in the Bible but they all appear to be living after the captivity or we know even less about them other than their name, so we can ignore them.]
So here we have it. Ezias is referred to in the Book of Mormon as a prophet who testified of the coming of the Son of God. The only thing we can say for sure is that Ezias is a Hebrew name and is shared with several people who are mentioned in the Bible. Of those mentioned most can be eliminated since they lived after the Babylonian captivity, and hence the Nephites would not have known about them. There are a few that cannot be considered to be prophets by any stretch of the imagination. A few more that we know nothing about. And finally there is "Uzzi" who is one of descendants of Aaron and may (or may not, depending on who you believe) have been the high priest of the tabernacle.
We definitely do not know enough to positively identify Ezias with anyone mentioned in the Bible, but by looking at the name and realizing that the same Hebrew name is spelled many different ways in English we have at least one person who might be considered to be a candidate for the Ezias mentioned in the Book of Mormon. Uzzi, who may have been a high priest, does seem to have the credentials to be a prophet who testified of the coming of the Son of God. Still, we will never really figure it out until we get some more records that contain more information than we now have. The brass plates would be nice, so maybe someday. In the end perhaps Ezias, who is only mentioned once in the Book of Mormon, is a little less anonymous than we think he is.