The typesetter for the 1858 Wright edition accidentally misread world as word. There may have been some marginal influence here from the well-known phrase “and the word was” in John 1:1: “In the beginning was the Word and the Word was with God and the Word was God”. The passage here in Jacob 4, of course, refers to Genesis 1, where God spoke and created both the world and man (as in verse 1, “In the beginning God created the heaven and the earth”; and in verses 26–27, “and God said let us make man in our image … so God created man in his own image”).
Also relevant to the creation account in Genesis 1 is an error that Oliver Cowdery initially made when he copied this passage from 𝓞 into 𝓟—namely, when he initially wrote “and man was” but then almost immediately corrected his error by supralinearly inserting the word created (the level of ink flow is unchanged). Oliver’s error was undoubtedly influenced by the partial parallelism of the previous clause (where the word created does not appear):
to speak and the world was
and to speak and man was created
Summary: Maintain the original text in Jacob 4:9, “and the world was … and man was created”.