Here in his editing for the 1837 edition, Joseph Smith changed the word constrain to restrain. In the original text of the Book of Mormon there were no occurrences of the word restrain. Joseph Smith also changed two other examples of constrain to restrain:
The obvious meaning of the word constrain in these three cases is ‘to prevent or to stop’ rather than the expected ‘to force’. According to the Oxford English Dictionary, one of the meanings of constrain is ‘to restrain within bounds, to limit’ (see definition 8d), which is essentially the meaning of constrain in these three Book of Mormon examples. All the other meanings of constrain in the Book of Mormon text have the meaning of ‘to force’, and thus Joseph Smith did not change any of these other examples to restrain. The critical text will restore the original cases of constrain that have the meaning ‘to prevent or to stop’.
Summary: Restore the original constrain in the three places where Joseph Smith emended constrain to restrain (here in 2 Nephi 1:26 as well as in Ether 12:2 and Ether 13:31).