Mary sends Jesus out to play with the caution, "Let me hear no ill of you when I come home." Some rich kids taunt Jesus that he is just a nobody, "born in an oxen's stall." After Jesus builds a bridge of sunbeams and the nasty little rich kids run over it, the bridge vanishes and they all fall in the river "and drownded were all three".
Mary needless to say is not pleased, and she pulls a withy (a willow branch) from the garden and whips Jesus with it. He curses the willow tree -
"O bitter withy, o bitter withy, that makes me so to smart,
The withy shall be the firstest tree, to wither from the heart."
I think Steeleye Span also did a version more recently.
“The Bitter Withy” doesn’t sound very Christ-like. :/