![St Luke the Evangelist](http://www.ststeve.com/wp-content/uploads/2016/10/St_Luke_the_Evangelist-295x300.jpg)
St Luke the Evangelist (Icon from the royal gates of the central iconostasis of the Kazan Cathedral in Stt Petersburg), by Vladimir Borovikovsky (1757–1825). From Wikipedia.
¶ Or this:
Almighty God, who calledst Luke the Physician, whose praise is in the Gospel, to be an Evangelist, and Physician of the soul: May it please thee, that, by the wholesome medicines of the doctrine delivered by him, all the diseases of our souls may be healed; through the merits of thy Son Jesus Christ our Lord. Amen.