Very interesting question… Short answer, there are two versions of this waiata… The kupu of this waiata are a loose translation from a Scottish Hymn ‘Abide with Me’. The version made popular by Sir Howard Morrison used the Melody from a Swedish Hymn called 'How Great Thou Art'. The version we sing has the melody and kupu from ‘Abide with Me’. Go check it out. Here is some more info on the waiata if you are interested… www.folksong.org.nz/whakaaria/index.html