The single most time-consuming part of the Daily Office is the reading of the two lessons of Scripture. This indicates to the worshiper that this is a high point in the liturgy. Furthermore, where the majority of the liturgy is relatively static from day to day, the content of the lessons is appointed by a Daily Office Lectionary such that every morning and evening throughout the year has its own unique set of lessons. This suggests that the public reading of Scripture is even the highest point in the Office liturgy.
The tradition, with very few exceptions in modern Prayer Books, is that the first lesson is from the Old Testament and the second is from the New. This allows for multiple readings of the New Testament in a year (originally three, now two) and one read-through of the Old Testament in the year. Several chapters from several books have been omitted from the Daily Office Lectionary in every Prayer Book, most notably Leviticus, Numbers, and Ezekiel. Further examination on the lectionary itself will have to be provided later; here it should suffice to note that the basic pattern of Old & New Testament readings each day provides both a deep familiarity with the contents of the New Testament and a cursory-but-constant familiarity with the Old Testament.
Because the Daily Office Lectionary is designed to read through the Bible in continuous readings, there should be no attempt to harmonize the two lessons on any given day; they are independent of one another, and only overlap in theme or content on a very few holy days in the year.