Here we have an example of uniqueness in the text: only in 1 Nephi 7:19 do we have the phrase “to lay hands (up)on someone” (with the meaning ‘to grab someone with the intent to harm or control’). Everywhere else the text includes a possessive pronoun before hands:
to lay their hands (up)on someone 16 times
to lay your hands (up)on someone 2 times
We are always going to find examples of unique expressions in the text, and we need to resist the temptation to eliminate their uniqueness (unless of course there is something demonstrably wrong with a particular unique expression). Here in 1 Nephi 7:19, it is theoretically possible that the original text itself read “and sought to lay their hands upon me”. One could argue for this emendation since similar usage in the text follows this pattern, including the following examples from 1 Nephi:
Although “lay hands” occurs only once in the Book of Mormon text, it is common in the King James Bible:
to lay their hands (up)on someone 3 times
to lay hands (up)on someone 13 times
In fact, when preceded by the verb seek (as here in 1 Nephi 7:19), similar examples in the King James Bible have only “lay hands”:
Of course, the commonness of this expression without the possessive pronoun could have led scribe 3 of 𝓞 to accidentally drop the their in 1 Nephi 7:19.
There are two similar examples involving the verb seek in the Book of Mormon:
The first example is interesting because it shows scribe 2 of 𝓟 initially writing the text without the their, but then immediately inserting it. Undoubtedly the original manuscript for Alma 9:32 had the their. One could view the temporary loss of the their in 𝓟 as evidence of the scribes’ tendency to drop the their in the expression “lay their hands upon someone”. On the other hand, we have no specific evidence that scribe 3 of 𝓞 tended to drop possessive pronouns.
Once more we have an example (namely, here in 1 Nephi 7:19) where there may be an early error in the transmission, but we cannot be sure. In order to keep some control over emendation, we generally accept the earliest textual reading as the original reading unless (1) there is something clearly wrong with that reading, and (2) we can reasonably explain that reading as an error in transmission. But there is nothing at all wrong with having 1 Nephi 7:19 read as simply “lay hands”.
Summary: Retain the unique phraseology “lay hands” in the original manuscript for 1 Nephi 7:19 since there is nothing wrong with it, even though it may be a scribal error for “lay their hands”.