One way to categorize how Christians in antiquity, especially the 1st-3rd centuries CE, understood the idea of a Bible is through three categories: normative, authoritative, and Scriptural. Normative means the tradition is standard and accepted amongst many. Authoritative means the tradition is standard and carries the an authoritative status. Authoritative can either be in a written text, or not. Scriptural means the understanding of a body of literature compiled into one, coherent piece. Scriptural does include the idea of authoritative tradition; however, the movement from authoritative to Scriptural results in the importance of the written material.
One of Origen’s letters, Exhortation to Martyrdom, offers some insight into this question. I won’t cite the text for the sake of time. This is mainly because I want to work out this idea in my own head.
Throughout the letter, he consistently speaks about what Jesus spoke, what Paul spoke, and even what the book of Revelation spoke. Obviously, the “speaking” done by Paul, Jesus, and Revelation occurs through the medium of a text. On the other hand, the Hebrew Bible is a written text. When referencing the Hebrew Bible, Origen references it as a written, material thing. Although he sometimes talks about what Yahweh said to Moses, it is a reference to a story told through a written, material tradition.
In other words, references to what we call the New Testament tend to be understood stood as an authoritative tradition. Even though they have material texts, the texts are simply a medium for a spoken, authoritative tradition. Distinct from these, references to the Hebrew Bible tend to be understood as written text. These texts were written in the past and were now relevant for Origen. As far as I am aware, they are not reference as “spoken” in this letter (i.e. “Thus, Moses speaks”).
In short, based on my short reading of Origen, the New Testament traditions are part of an authoritative tradition, which found its way to Origen through text. The Hebrew Bible is part of Scriptural in the sense that it is a written, material thing. This written, material thing is the object from which Origen draws meaning from the written word for his day. In reference to New Testament literature, Origen draws from the spoken word for his day, which just happens to be spoken through a medium of literature.