St. John Cassian on anger

If you fast for quarrels and fights
and you strike a humble person with your fists,
why do you fast for me as you do today
so that your voice may be heard by its clamor?

--Isa 58:4

When the aged John, who was superior of a large monastery and of a quantity of brethren, had come to visit the aged Pæsius, who was living in a vast desert, and had been asked of him as of a very old friend, what he had done in all the forty years in which he had been separated from him and had scarcely ever been disturbed in his solitude by the brethren: “Never,” said he, “has the sun seen me eating,” “nor me angry,” said the other.

--The Institutes of St. John Cassian 5.27

On the threshold of the Fast, I've been re-reading some of St. John Cassian, particularly his books on the eight principal faults. I planned to read them for Lent anyway, but it occurred to me that I could use a refresher before I start the Fast, so that my attitude is right (or at least better) as I begin. Perhaps no more is this the case than with the fault of anger, since it's so easy to get snippy when one is hungry. The whole book on anger is worth reading several times, but this one, short chapter stood out to me:

Or how can we think that the Lord would have [anger] retained even for an instant, since He does not permit us to offer the spiritual sacrifices of our prayers, if we are aware that another has any bitterness against us: saying, “If then thou bringest thy gift to the altar and there rememberest that thy brother hath aught against thee, leave there thy gift at the altar and go thy way; first be reconciled to thy brother, and then come and offer thy gift” (Matt 5:23-24). How then may we retain displeasure against our brother, I will not say for several days, but even till the going down of the sun, if we are not allowed to offer our prayers to God while he has anything against us? And yet we are commanded by the Apostle: “Pray without ceasing” (1 Thess 5:17); and “in every place lifting up holy hands without wrath and disputing” (1 Tim 2:8). It remains then either that we never pray at all, retaining this poison in our hearts, and become guilty in regard of this apostolic or evangelic charge, in which we are bidden to pray everywhere and without ceasing; or else if, deceiving ourselves, we venture to pour forth our prayers, contrary to His command, we must know that we are offering to God no prayer, but an obstinate temper with a rebellious spirit.

--The Institutes of St. John Cassian 8.13

Ouch! He doesn't leave much room here, does he? St. Cassian goes on at the end of the book on anger to raise this point as one of our best tools for self-correction. If we remember what an impediment anger is to prayer, how can we possibly let it go unchecked?

I would recommend as well a series of talks by now-Met. Jonah of Washington and New York, in which he discusses resentment and reacting (in anger) as obstacles to achieving inner stillness.