in fields ... as they ... lay keeping their sheep ... on a cold winter 's night that was so deep ... '' stu joined in on the chorus , his voice not as good as tom 's but mixing well enough to suit the two of them , and the old sweet hymn drifted back and forth in the deep cathedral silence of christmas morning : `` noel , noel , noel , noel ... christ is born in israel ... `` `` that 's the only part of it i can remember , '' tom said a little guiltily as their voices drifted away .