Here are some things.
The first is from Caxtons epilogue to the printing. He is talking about whether Arthur was real and noting various evidence that he was, and he gets to this bit (my italics);
"..and yet of record remain in witness of him in Wales, in the toune of Camelot, the great stones and marvelous works of iron lying under the ground, and royal vaults which diverse now living hath seen."
Marvelous works of iron?
Second, a quote from the "Buke of Knychthede" (Properties of the Noble order and Office of Knychthede.) by Gilbery Hay
"Item, office of knighthood is to maintain and defend widows, maidens, fatherless and motherless bairns, and poor miserable persons and pitiable, and to help the weak against the stark, and the pure against the rich; for oft-times sick folk are, by more stark than they, beaten and robbed, and their goods taken, and put to destruction and poverty, for fault of power and defence.
For right as the hewing axe is ordained to cut down trees that hinder ploughing of lands, and carts and chariots and merchandises to pass through the forests, so is the sword of knighthood ordained to cut away and destroy the wicked unworthy weeds and vines of thorns of evil men that hinders labourers, merchants, traitors to travel through the world which is as a forest and wilderness when it is not well tended; of the which evil men should be weeded out by knights, keepers of the law, that good men might live in shelter; and he that is a knight, and does not this, but does even the contrary, should be taken by the prince, or by other worthy, faithful, and honourable knights, and put till dead.
For when a knight is a reaver, or a thief, or a traitor or a murderer, or a lollard, schismatic or heretic, or in such crimes openly known and proved, then he is unworthy to live, but to be punished in example of others that defoul that most noble and worthy order and abuse it against the points and the properties of that order.
Third, one of Malory's few direct interjections into the text, from the final book:
"Then came there word unto Sir Mordred that King Arthur had raised the siege from Sir Launcelot and was coming homeward with a great host to be avenged upon Sir Mordred; wherefor Sir Mordred made great writs upon all the barony of this land. And much people drew unto him; for then was the common voice among them that with King Arthur was never other life but war and strife, and with Sir Mordred was great joy and bliss.
Thus was King Arthur depraved and evil said of - and many there were that king Arthur had brought up out of nought, and given them lands, that might not then say him a good word.
Lo, ye, all Englishmen, see not what mischief here was? For he that was the most king and noblest knight of the world, and most loved the fellowship of noble knights - and by him they were all upholden - and yet might not these Englishmen hold them content with him.
Lo, thus was the old custom and usage of this land; and men say that we of this land have not yet lost that custom. Alas, this is a great default of us Englishmen, for there may be no thing us please no term.
And finally, in his largest interjection, the reason, I think that so many people who read Malory are caught up in the mystery of the man, especially for those of you who remember his rap sheet.
This is the criminal and possible rapist in prison five hundred years ago, talking about a time he imagined about a thousand years before he was born:
"And thus it passed on from Candlemas until after Easter, that the month of May was come, when every lusty heart begins to blossom and to burgeon. For, like as trees and herbs burgeon and flourish in May, in like wise every lusty heart that is any manner of lover springs, burgeons, buds and flourishes in lusty deeds.
For it gives unto all lovers courage, that lusty month of May, in something to constrain him to some manner of thing more in that month than in any other month, for diverse causes: for then all herbs and trees renew a man and woman, and in like wise lovers call to their mind old gentleness and old service, and many kind deeds that was forgotten by negligence.
For, like as winter raisure does always erase and deface green summer, so fairs it by unstable love in man or woman: for in many persons there is no stability, for we may see all day, for a little blast of winters raisure, anon we shall deface and lay apart true love, for little or naught, that cost much thing.
This is no wisdom nor no stability, but it is feebleness of nature and great dishonour, whomever useth this.
Therefore, like as May month flowers and flourishes in every mans garden, so in like wise let every man of honour flourish his heart in this world, first unto God, and next unto the joy of them that he promised his faith unto. For there was never honourable man nor honourable woman , but that they loved one better than another; and honour in arms may never be foiled. But first reserve the honour to God, and secondly thy quarrel must come of thy lady - and such love I call virtuous love.
But nowadays men can not love seven night but they must have all their desires. That love may not endure by reason; for where lovers be soon accorded and hasty, heat soon cools. And right so fairs the love nowadays, soon hot, soon cold: this is no stability. But the old love was not so: for men and women could love together seven years, and no lecherous lust was between them - and then was love truth and faithfulness.
And so in like wise was used such love in King Arthurs says. Wherefore I liken love nowadays unto summer and winter: for like as the one is cold and the other hot, so fairs love nowadays.
And therefore all you that be lovers, call unto your remembrance the month of May, like as dead Queen Gwenyver, for whom I make a little mention, that while she loved she was a true lover, and therefore she had a good end."