Definition of lectionary:
[quote]
Lectionary. (See PERICOPE; CHURCH YEAR; LITURGY.) A book containing lists of lessons from Holy Scripture or the lessons themselves, for use in the worship of God. Selections from the Old Testament were assigned to days in the worship of the synagogue, and traces of a like custom extend back to the second century.
Edward T. Horn, “Lectionary,” ed. Henry Eyster Jacobs and John A. W. Haas, The Lutheran Cyclopedia (New York: Charles Scribner’s Sons, 1899), 273.
Definition of ordo:
[quote]
Ordo (Latin word signifying order).—Little book which is made anew every year, to indicate to the ecclesiastics the manner in which they should say the office every day.
John Thein, Ecclesiastical Dictionary: Containing, in Concise Form, Information upon Ecclesiastical, Biblical, Archæological, and Historical Subjects (New York; Cincinnati; Chicago: Benziger Brothers, 1900), 511.
Because the two are combined in Logos, the results include 1 occurrence for the generic liturgical date and additional occurrences for each year in which it occurs that is currently included in the lectionary.
1. One can search for a biblical passage against a collection of type:lectionary. Because of the structure of the Lectionary each match that is shown is actually a double match.

2. Or one can use the label search which is described (incorrectly) in Help. (Remove the second set of quotes in the example ... I have corrected it here).
[quote]
Lectionary Reading
Lectionary resources consist of sets of readings (or “lessons”) to be read on particular occasions. Each reading has a title and a list of references. Lectionary Reading labels are used to precisely mark up the title and references for each reading in a lectionary resource. This populates the Lectionary section in the side bar of the Home Page. Note: Liturgical date is not currently included in these labels.
• Title ~ "" — the kind of reading, such as "Old Testament" or "Gospel"
• References ~ <Bible ...> — list of references contained in the reading
For example:
• {Label Lectionary Reading WHERE Title ~ "Old Testament" AND References ~ <Bible Isaiah 60>}
Interactive Dataset Labels
Logos 6 Help (Bellingham, WA: Faithlife, 2015).
Here one get half the matches in count but exactly the same occurrences as in the first search.
