The keyword term "September 11th prayer" functions as a noun phrase. The main point and grammatical head of this phrase is the word "prayer," which is a noun. The term "September 11th" acts as an adjectival modifier, specifying the type or subject of the prayer.
In this construction, "September 11th" is a proper noun (referring to a specific date) that functions as a noun adjunct or attributive noun. It modifies the head noun "prayer" by providing context. This grammatical structure is common in English, where one noun is used to describe another (e.g., "kitchen sink," "business meeting"). The modifier ("September 11th") narrows the scope of the head noun ("prayer"), distinguishing it from prayers related to other topics or occasions.
Because the main point of the keyword is a noun, the article should focus on the prayer as a concept, event, or text. The content should define, describe, or analyze the prayer(s) associated with the September 11th attacks. This includes discussing their themes (e.g., remembrance, peace, healing for victims), their use in commemorative services, or their significance as a cultural and religious response to the tragedy.