Jacob is afflicted with the same problem we have seen Nephi have with writing on the plates. He begins in one place, is drawn into a tangential path and then finally gets back to his original intent. In this case, the tangent is more like a major detour. Jacob begins this section with a personal declaration. This kind of introduction by name occurs when a formal declaration is to be given. While Jacob begins this verse with a construction that is intended to introduce this declarative section, he begins a parenthetical comment that sidetracks his train of thought. In the English grammatical structure it leaves him with an incomplete sentence that simply hangs, awaiting a distant conclusion. We will not receive a clear notice of when Jacob returns to his original intention. The detour melds deftly back to the original theme, suggesting that while Jacob is taking a slight detour, his thought is not derailed, but perhaps running just a little faster than he can write on the plates.
Jacob's aside deals with the plates. Jacob notes that it is difficult to write on the plates, but that he considers it important to do so. While Jacob begins this simple aside with the declaration - almost - apology that he writes little due to the difficulty of writing on the plates, he begins to ruminate on the importance of the plates, and essentially witness as a prophet of God to their essentiality.