More commonly titled "Watt's Cradle Hymn" or "Watt's Cradle Song". An American version is in The New Oxford Book of Carols (no. 115), but the tune there (similar to "Aunt Rhody") is different. Doc's version is on Doc Watson: On Praying Ground (Sugar Hill).

CHRISTMAS LULLABY (Doc Watson version)

Hush, my babe, lie still and slumber,
Holy angels guard thy bed.
Heavenly blessings without number
Gently stealing on thy head.

How much better art thou attended
Than the Son of God could be,
When from heaven He descended
And became a child like thee?

Soft and easy is thy cradle--
Coarse and hard the Savior lay,
When His birthplace was a stable,
And His softest bed was hay.

Hush, my babe, lie still and slumber,
Holy angels guard thy bed.
Heavenly blessings without number
Gently stealing on thy head.

Gently stealing on thy head.

~Masato