Basically, to plight one’s troth means basically the same as ‘to pledge an oath [to stay together]‘. I always think of it in terms of the Anglo-Saxon culture as they were very keen on making deadly serious oaths of loyalty and fealty and so on. It’s a pretty old phrase, anyway – and yes, the concept of plight is the same as ‘to be in a terrible situation’, whichmay give you pause for thought about the whole marriage thing!

(If you’re really bored, this link might enlighten you a bit – http://www.chass.utoronto.ca/~cpercy/courses/1001TierneyHynes.htm )

• But which soon goes off on a rather alarming tack:

I hate to say it, but most of the elements you objected to (“those who lack the gift of continence”; “love their wives as their own bodies”; “women, don’t plait your hair”) come pretty directly from the Bible.

But I don’t know about the line, “be not bitter against them”. Sounds to me like it was written by someone with a particularly bad marriage.