Here the earliest text reads “the great and chief judge”. In the 1837 edition, the and was omitted, perhaps intentionally. This change suggests the possibility that here the original text read without the and as “the great chief judge”. There are, as one might expect, numerous examples in the text where we have “great and ”, as in Helaman 13:18: “our great and true God”. In the case of “great chief judge”, on the other hand, one could consider chief judge as a compound noun modified by the adjective great.
In the Book of Mormon, the adjective great, whenever it modifies a noun representing a political position, can be thought of as meaning ‘supreme’. We have several instances of such usage in the earliest text:
But there are no other examples of great modifying chief judge as a unit or judge alone. Note that in these three other examples the form is always “the great X of Y”, which is different in that respect from the form here in Helaman 9:10 (“the great and chief judge which had been slain”).
A parallel example to the earliest reading in Helaman 9:10 can be found in 2 Nephi; in that instance, the original and has been retained:
Here we have one more instance of “great and ”; not only does the noun judgment modify day, but great does too. And we can find support for the phrase great day referring to the day of judgment; note, in particular, that the first of the following examples has an instance of conjoined great modifying day (marked below with an arrow):
There are five other instances in the text of “great and last day”, plus two of “great and dreadful day” and one of “great and coming day”, all in reference to the “great day” of judgment. These other examples of “great and day” further support the expression “great and judgment day”. And the latter supports the expression “the great and chief judge” here in Helaman 9:10. Thus the critical text will restore the original and between great and chief in “the great and chief judge”.
Summary: In accord with the earliest textual source (the printer’s manuscript), restore the and in Helaman 9:10 (“the great and chief judge”); such usage is found elsewhere in the text, as in 2 Nephi 9:22 (“the great and judgment day”).