Here the 1837 edition omitted the preposition unto, probably unintentionally. It has never been restored to either the LDS or the RLDS text. More generally, for all examples in the text of “give someone commandment(s)” (that is, where the indirect object comes before the direct object), we find an equal number of examples with and without the preposition unto in the original text (seven of each possibility). Moreover, in this same chapter there is one more of these where the unto was omitted in the textual history:
In this instance, the unto was omitted in the 1840 edition, and the subsequent RLDS textual tradition has maintained the shorter reading.
If we consider cases that refer to giving law, all the other examples are in the passive; for this expression, we get even more variety with respect to the preposition (there is one case of to):
There is one instance in 3 Nephi 12–14 where unto occurs in the Book of Mormon text but is lacking in the corresponding King James passage:
3 Nephi 14:7 Matthew 7:7
ask and it shall be given unto you ask and it shall be given you
Either reading—with or without unto —is possible in the Book of Mormon text, so for each case of unto, the critical text will rely on the earliest textual sources in determining whether this preposition should be included or not. Thus unto will be restored here in 3 Nephi 12:19.
Summary: Restore in 3 Nephi 12:19 the preposition unto, the reading of both 𝓟 and the 1830 edition (thus “I have given unto you the law and the commandments of my Father”).