In medieval illuminated manuscripts the illuminated Q was used for Psalm 52:

“Quid gloriaris in malitia, qui potens es in iniquitate?”

Why do you glory in malice, you who are mighty in iniquity?

Psalms, chapter 52

For the leader. A maskil of David,

when Doeg the Edomite entered and reported to Saul, saying to him: “David has entered the house of Ahimelech.”

I

Why do you glory in what is evil, you who are mighty by the mercy of God?

All day long

you are thinking up intrigues;

your tongue is like a sharpened razor,

you worker of deceit.

You love evil more than good,

lying rather than saying what is right.

Selah

You love all the words that create confusion,

you deceitful tongue.

II

God too will strike you down forever,

he will lay hold of you and pluck you from your tent,

uproot you from the land of the living.

Selah

The righteous will see and they will fear;

but they will laugh at him:

“Behold the man! He did not take God as his refuge,

but he trusted in the abundance of his wealth,

and grew powerful through his wickedness.”

III

But I, like an olive tree flourishing in the house of God,

I trust in God’s mercy forever and ever.

I will thank you forever

for what you have done.

I will put my hope in your name—for it is good,

—in the presence of those devoted to you.