I have translated that letter in "Conversations of the Universe"
**SPOILERS**
To Thine Own Eyes, Prophet of Mercy
Dearest Brother,
I hope this finds you well. My sorrow
and anger precede me with regard to the
atrocity and heresy at Halo. We shall avenge
this destruction with some of our own.
Work proceeds apace (ahead read it wrong sorry) on our battle plan. The
Sangheili will do what is asked of them, and
the Jiralhanae will show the humans what our
strength looks like at close quarters.
But this message concerns neither the
planning nor the discovery of the human
homeworld. Rather I question Brother Regret's
sympathy for this great purpose.
I am aware of his tenacity and ambition,
but I beleive his youth and feckless reacting
may prove to be great risks to the perfection
of this undertaking. You have noted his
rashness in the past, and yet neither of us
has acted.
I suggest that we continue as planned, but
we would both do well to play mind to Brother
Regret, and provide wisdom and guidance
as needed. This matter is too important to
be left to inexperienced hands. Piety is no
substitute for wisdom.
Perhaps I worr too much, you know that
I embrace caution but we cannot have
inexperience or arrogance at this great
journey.
Be pure, be upright, and never rest
By my own hand
Prophet of Truth
**end spoilers**
that was too much work for too little profit. oh well. it was fun to do. reminded me of the Cryptonomicon.