By extension from the Biblical phrase “break the staff of bread” (Hebrewמַטֶּהלֶחֶם(maté lékhem)), staff(“long, straight rod”) in this context meaning something that acts as a support:[1] see, for example, Leviticus 26:26 (King James Version; spelling modernized): “And when I have broken the staff of your bread, ten women shall bake your bread in one oven, and they shall deliver you your bread again by weight: and ye shall eat, and not be satisfied”;[2] and Ezekiel 4:16: “[…] Son of man, behold, I will break the staff of bread in Jerusalem, and they shall eat bread by weight, and with care, and they shall drink water by measure, and with astonishment:[…]”.[3] Compare Egyptianḫt n ꜥnḫ(“grain; food”, literally “stick or wood of life”).
1831 July 15, “Of the Blood”, in Western Journal of Health, volume 4, number 1, L. B. Lincoln, page 38:
It was reserved for Christians to torture bread, the staff of life, bread for which children in whole districts wail, bread, the gift of pasture to the poor, bread, for want of which thousands of our fellow beings annually perish by famine; it was reserved for Christians to torture the material of bread by fire, to create a chemical and maddening poison, burning up the brain and brutalizing the soul, and producing evils to humanity, in comparison of which, war, pestilence, and famine, cease to be evils.
The round calabash is a perfect image for the feminine womb, within which the arduously pounded taro is contained and then offered as the very staff of life.
1998 February 18, Colin G. Calloway, New Worlds for All: Indians, Europeans, and the Remaking of Early America, JHU Press, →ISBN, pages 51–52:
Corn was the staff of life for many Indian people before contact, and it became the staff of life for many European colonists. Corn was higher in nutrition than most other grain crops. John Lawson, who travelled in South Carolina and into the interior Indian country in 1701, was one of the many colonists who sang the praises of corn.
The Holy Bible,[…] (King James Version), London:[…]Robert Barker,[…], 1611, →OCLC, Leviticus26:26, column 1: “And when I haue broken the ſtaffe of your bread, ten women ſhall bake your bread in one ouen, and they ſhall deliuer you your bread againe by weight: and ye ſhall eate, and not be ſatiſfied.”
The Holy Bible,[…] (King James Version), London:[…]Robert Barker,[…], 1611, →OCLC, Ezekiel4:16, column 2: “[…] Sonne of man, behold, I wil breake the ſtaff of bread in Jeruſalem, and they ſhall eat bread by weight, and with care, and they ſhal drinke water by meaſure, and with aſtoniſhment:[…]”