Here the compositor for the 1892 RLDS edition accidentally set may as now. Perhaps he expected the clause to begin as “and now the Lord Jesus Christ grant that …”, an alternative optative expression for “and may the Lord Jesus Christ grant that …”. Of course, many Book of Mormon clauses begin simply with “and now”. Whatever the source of the error here in Mormon 9:37, the 1908 RLDS edition restored the correct may, which is found in two other optative clauses later in the passage.
Summary: Maintain in Mormon 9:37 the use of the modal verb may at the beginning of the verse (as well as the two other times that it occurs in this verse).