Restriction on wearing tartan "the Devil's oath"

[Graham]

Interesting Tom, what a terrible oath to swear. I find it hard to believe how any Scot could, surely it is a denial of all that is Scottish!, well certainly the tartan clause.

[Andrew Green]

Of course there is also the dying as a coward part, along with the whole in a land not your own thing. That's two very important aspects. For someone with a sense of martial pride, dying as a coward would be a grave insult indeed.