the arm of a person or creature, the limb from shoulder to hand
TranslatabilityDirectCertaintySettled
At its plainest this is the body part: the arm, sometimes the forearm or upper arm, the limb a person uses to grip, strike, lift, and hold. When Samson's bonds melt off, they fall from his arms. When an arrow runs a man through, it pierces between his arms. A capable woman braces her arms for work.
Because the arm is where a body's force is felt, the word slides easily from the limb itself to the strength in it, and most of its uses lean that way. This first meaning keeps to the literal limb, the places where the arm is simply an arm.
the shoulder or foreleg of an animal given as a priestly portion
TranslatabilityDirectCertaintySettled
In the rules for sacrifice the same word names a cut of meat: the shoulder, or foreleg, of the animal. It is set apart as a portion that goes to the priest. This is a narrow, concrete use tied to the offerings, where the arm is the animal's limb rather than a person's.
Num 6:19Deu 18:3
3
strength or power, pictured as the arm that wields it; often military or political might
TranslatabilityPartialCertaintySettled
Far more often than the limb itself, the word stands for the force the arm carries: a person's, a nation's, or an army's power to act, to fight, to dominate. To break someone's arm is to cripple their strength; a strong arm is a hand that gets its way. Pharaoh's broken arms are his shattered military might; the arms that scatter before an enemy are forces that collapse.
The word can carry a warning as well. To make human strength your trust, to lean on your own arm or another's, is set against trusting God. The same image runs from the muscle that bends a bow of bronze to the raw power of kings and kingdoms.
the arm of the LORD: God's own power, especially to rescue and to judge
TranslatabilityPartialCertaintySettled
The word's most weighty use is for God. The arm of the LORD is God's power put into action, the strength by which he saves his people and brings down their enemies. When the Bible recalls the rescue from Egypt it speaks again and again of an outstretched arm, a strong arm that reached down and pulled a people out.
The prophets stretch the image further. The arm of the LORD is bared like a warrior rolling up a sleeve, laid open for all the nations to see God act. It works salvation when no human help is found, and it is the very thing people fail to believe in when they reject God's saving work. To picture God's might as an arm is not to give God a body; it is plain, bodily language for a power that does real things in the world.
Names a literal body part, the arm, so it pictures strength as something with a visible limb that reaches out, strikes, and holds. It can even mean the shoulder portion of a sacrificed animal.Num 6:19Deu 18:3Jdg 15:14
Becomes the standing image for God rescuing his people: he reaches out a bared arm to save, an arm that can be raised, broken, or stretched out in action.Exo 6:6Isa 51:9Isa 53:1Psa 98:1
Both
Both stand for the might that wins a victory, and the two are paired together to insist that no human force can match God's power.Jer 27:5Jer 32:17Dan 11:15
Both can prop up the weak: one gives an arm to lean on, the other gives strength to those who have none, and a single verse can offer both at once.Job 26:2
Names strength in the abstract, the capacity or vigor a person or thing has, with no picture of a body part. It is the energy you spend and can run out of.Gen 49:3Jdg 16:51Sa 28:20
Stretches to the productive capacity of things that are not people: the yield the ground is able to give, and the resources or wealth a nation can muster.Gen 4:12Lev 26:20Ezr 2:69
zero'a in the other biblical languages
βραχίωνGreek“arm”the Greek word for arm; in the New Testament it appears in the phrase "the arm of the Lord," carrying over this Hebrew image of God's saving power
What scholars say about zero'a
The standard lexica (HALOT, BDB, DCH) treat זְרוֹעַ as a single noun, "arm," with a coherent range running from the literal limb to the strength it carries, and into figurative power, especially the power of God. They also note the cultic use for the shoulder or foreleg of a sacrificial animal given to the priest. TDOT traces the heavy theological weight the word carries in describing God's saving acts, above all in the Exodus formula of the outstretched, strong arm and in Isaiah's "arm of the LORD."