The 1953 RLDS edition accidentally replaced the plural words with word. This reading in the singular is obviously quite unexpected, especially since elsewhere the text has only “all the words” (18 times), never “all the word”. For a similar typo in the 1953 RLDS edition, see 2 Nephi 6:1.
Summary: Maintain the plural “all the words” in 2 Nephi 5:4.