Once more we have a case of commandment instead of commandments in the original text. Here the scribe in 𝓞 is the unknown scribe 3. As noted in the discussion of “without the wall” in 1 Nephi 4:5, this scribe frequently drops off the plural s, so one could argue that the reading in 𝓞 is a scribal mistake. On the other hand, Oliver Cowdery himself sometimes changes commandment to commandments (see the discussion under 1 Nephi 3:16). Once again the context allows for a singular form, especially since Nephi refers in the preceding clause to the Lord having “commanded us to do this thing”. In other words, Nephi is telling Zoram about the specific commandment to get the plates of brass from Laban. Thus the singular commandment is perfectly fine and should be retained.
Summary: Restore the singular commandment in 1 Nephi 4:34 since the context implies the singular.