This paper provides an analysis of the anupubbikatha, the Buddha's method of addressing his teaching to the lay community in Pali texts. In the first section, an analysis will be presented of the anupubbikatha which occurs in the biography of the Buddha as contained in the Pali Vinaya (Vinaya. I pp. 1-44). A parallel description occurs in the Dharmaguptaka-Vinaya (四分律) and Mahisasaka-Vinaya (五分律), although the presentation is different. Through a closer examination of this difference, it will be shown that the anupubbikatha is closely related to the Four Noble Truths as described in the Buddha's first sermon. In the second section, it will be seen that the anupubbikatha is used as the Former Buddha's first sermon in the Mahapadnasuttanta (DN. 14, DN. II pp. 1-54). This will allow us to speculate that the value of this sermon gradually increased over the course of the formation of the PAli Canon. Thus, by showing that the anupubbikatha presupposes the description of the Buddha's first sermon, it will be argued that the anupubbikatha takes on the function of presenting the Four Noble Truths, as described in the Buddha's first sermon, in a more intelligible fashion.