Therefore thus says the Lord, who redeemed Abraham, concerning the house of Jacob: " . . . They will hallow My name, And hallow the Holy One of Jacob, And fear the God of Israel. These also who erred in spirit will come to understanding, And those who complained will learn doctrine.” (Is. 29)
The last line of this reading stands out. There is a tendency to pit doctrine against the liturgy and vice versa. These words show that there is no need for such a false dichotomy - the liturgy here sees doctrine as a good thing. Hence the lex orandi, lex credendi.
Traditionalists rightly point out that this reading is not part of the lectionary. Only the Gospel and Epistle are read. Even "traditionalist" Lutherans do not always follow the traditional route. That may be a Lutheran thing.
On a related note, I read something historical which helps provide a clue to the mystery why there seems to be a tension between exegetes and the liturgy, something I attributed in the past to merely a difference in focus. This is something with much history:
"It is with Origen that devotion to the letter of Scripture and concern to refer to the original text come to take on a new importance. Science will gain from this. But the living relationship between Scripture and tradition is on the way to being compromised." (Danielou, Couratin and Kent, 54)
This helps to explain the false tension today between liturgy is prayer and liturgy as mere structure. Rather, the liturgy calls on us to both "hallow [God's] name" and "learn doctrine." After all, faith "comes from hearing."