" Sister help to trim the sail"
1. Does 'trim' mean to cut?
This is a sailing reference. In general, the closer you sail to the wind, the closer the sails are pulled or trimmed to the midline of the boat. As you sail away from the wind, the sails are progressively let out. The exact position of the sails are based upon the direction and speed of the apparent-wind. "Jordan's river is chilly and cold"
2. Any significance about the river, Jordan's river?
" Milk and honey on the other side"
The River Jordan is often used as a metaphor for death. According to Slave Songs of the United States
, the "Michael" referred to in the song is the Archangel Michael
. In Christian tradition, Michael is often considered a psychopomp
, or conductor of the souls of the dead.
3. Any significance about 'milk' and 'honey'? Why not beef or lamb is mentioned? The reference is from the Bible.
"And I am come down to deliver them out of the hand of the Egyptians, and to bring them up out of that land unto a good land and a large, unto a land flowing with milk and honey
: unto the place of the Canaanites, and the Hittites, and the Amorites, and the Perizzites, and the Hivites, and the Jebusites." -- Exodus 3: 8 (KJV)
I hope this helps,