'Merry of soul'
I came across that phrase in a song called 'skye boat song', I have also learned that it's a quote from one of Stevenson's poems.
I understand that merry is an adjecctive that means happy ,and in all honesty that line sounds really beautiful to my ear, but isn't it wrong to say happy of soul shouldn't it be for instance with happiness of soul , with a happy spirit or happy in soul?
The whole stanza
'Sing me a song of a lad that is gone,
Say, could that lad be I?
Merry of soul he sailed on a day
Over the sea to Skye.'
Note1: I replaced merry with happy when giving examples because Im not used to using the word merry thus it's still a bit weird for me to use it.
Note2: I have already asked that question before on English Language And Usage Stack but for some reason the question was put on hold as off-topic. I think maybe because it is easy and should have been asked here so you will find me copying others comments from there thus seeming to answer my own question.