this video on youtube gives the translation to Gaelic by Bear McCreary on screen
https://www.youtube.com/watch?v=eJmny5Iy8gc

the chorus:

Seinnibh leam dàn
Gu nìghneag mo chridh
Nìghneag mo rùn 's mo ghraidh
Faicibh am bàt'
'S e togail bho thìr
Giùlan mo rìgh bho thraigh


another video includes the English lyrics by Robert Louis Stevenson (who didn't like Harold Boulton's original, I read) and Gaelic lyrics attributed to Gillebride MacMillan
https://www.youtube.com/watch?v=w40xS4CCwt4

Seinn dhom an duan,
Mun tè a chaidh air thìr,
Saoil am bu mise i.
Sheol i thar sàil,
's i chò faiteach na gràdh,
ò chàidh anull thar sàil,

Oiteag is stuagh, atadh is cuan,
beanntan an uisge is na grèine.
Gach nì a bha dhom math,
Gach nì a bha gun smàl,
Gach nì a bha gu math,
A-nis air falbh bhuam.