Primary and secondary source incorporation

My instructor wants two short essays on topics provided every week for tough online course I am taking. In the essay he requires we identify if the document were writing about is a primary or secondary source. I understand the differences but how do I incorperate this into my essay? Just saying "xyz document is a primary source" sounds awfully plain. If someone has any examples it would help.

Thank you for any help

Dear friend,

I want to send you a short passage, took from a trusted TOEFL book. You can use this for reference.

The scholarly method involves careful analysis and interpretation off information. Information must come from somewhere. These are the sources. There are three types of sources: primary, secondary, and tertiary. Primary sources come from documents created by people who witnessed events first hand. A person's diary is an example of a primary source. When information from primary sources is interpreted by others, it is called a secondary source. For example, if someone read that diary, compared it to newspapers from the same period and wrote about it, this would be a secondary source. If someone then read that secondary source and created a new document that would be a tertiary source.