Somebody somewhere has got to know what logic was applied in deciding how to arrange the readings for ordinary time. There are useful little charts laying out the readings at the Roman Catholic Lectionary Website. If you look at Ordinary Time - Year 1, you see that in the first nine weeks of Ordinary Time, the gospel marches through Mark, from chapter 1 through chapter 12. Halfway through week 7 this year, we start Lent, and then Easter, before resuming with week 9 after Pentecost. What happened to week 8?
Also note that for the first reading at weekday mass, the first through fourth week of Ordinary Time steps through the letter to the Hebrews. Weeks five and six feature Genesis, from creation through Noah. Weeks seven and eight has the book of Sirach, and week 9 features Tobit. (Note: if you're using a Protestant Bible, you might not find the books of Sirach and Tobit. They are among the deuterocanonical books that were rejected by Martin Luther.) But wait! Saturday of week six is not Genesis, but Hebrews. Why was Hebrew 11:1-7 inserted between Genesis and Sirach? Why wasn't that reading back in week 3, where it belonged? [Update: I should have read the passage before posting. It references back to Cain, Enoch, and Noah from Genesis. I suppose there was some logic in this case. Still, it looks out of place when just the book, chapter, and verse are listed in a table.]
Somebody somewhere knows what logic was applied that ended up in this schedule. Do you think maybe they could clue in the rest of us?