The St. Benedict medal and the peck

An email correspondent has drawn my attention to the St. Benedict medal.

On the obverse, St. Benedict is flanked by a serpent and chalice (symbol of pharmacy) and a raven (corvid). These symbols refer to two attempts to poison the saint -- first with poisoned wine, and then with poisoned bread that was providentially carried away by a raven before the saint could eat it.

On the reverse, we have the initials of a Latin prayer:

Crux Sacra sit mihi lux

Nunquam draco sit mihi dux

Vade retro Satana!

Nunquam suade mihi vana!

Sunt mala quae libas.

Ipse venena bibas!

In English:

May the Holy Cross be my light.

Never may the dragon be my guide.

Get back, Satan!

Never tempt me with vanity.

What you offer me is evil.

Drink your poison yourself!