Caesar DBG VI.14

Druides a bello abesse consuerunt

The Druids are accustomed to be absent from war

neque tributa una cum reliquis pendunt;

nor do they pay taxes together with the rest;

militiae vacationem omniumque rerum habent immunitatem.

they have exemption of the military and immunity of all affairs.

Tantis excitati praemiis

Having been excited by such great rewards

et sua sponte

and by their own accord

multi in disciplinam conveniunt

many gather in the discipline

et a parentibus propinquisque mittuntur.

and they are sent by parents and relatives.

Magnum ibi numerum versuum ediscere dicuntur.

There they are said to learn a great number of verses.

Itaque annos nonnulli vicenos in disciplina permanent.

And so some stay in the discipline for 20 years.

Neque fas esse existimant

Nor do they think that it is right

ea litteris mandare,

to entrust these things to letters,

cum in reliquis fere rebus,

although generally in remaining matters,

publicis privatisque rationibus

in public and private accounts

Graecis litteris utantur.

they use Greek letters.