Oliver Cowdery dropped the adverb now while copying from 𝓞 into 𝓟. The connecting phrase “and now” occurs hundreds of times in the text, so there is no reason why the now shouldn’t be restored here. One similar example has the demonstrative pronoun this acting as a direct object immediately following a sentence-initial “and now”, just like here in 1 Nephi 19:4:
Summary: Restore the now in 1 Nephi 19:4 that Oliver Cowdery accidentally omitted in his copying; the connecting phrase “and now” is very common in the Book of Mormon text.