Omer

An omer was a measure for grain, and Exodus 16 is where Scripture uses it. Israel was hungry in the wilderness, and the LORD told them to gather bread from the ground, “an omer for every man.” Verse 36 explains the unit: “an omer is the tenth part of an ephah.” The story turns on a small wonder: “he that gathered much had nothing over, and he that gathered little had no lack.” Each person ended with the same measure, and the chapter is worth reading start to finish.

4 verses

Exodus

Exodus 16:16

This is the thing which the LORD hath commanded, Gather of it every man according to his eating, an omer for every man, according to the number of your persons; take ye every man for them which are in his tents.

Exodus 16:17

And the children of Israel did so, and gathered, some more, some less.

Exodus 16:18

And when they did mete it with an omer, he that gathered much had nothing over, and he that gathered little had no lack; they gathered every man according to his eating.

Exodus 16:36

Now an omer is the tenth part of an ephah.

From Easton's Bible Dictionary

Matthew George Easton, 1897

A handful, one-tenth of an ephah=half a gallon dry measure (Ex. 16:22, 32, 33, 36)=“tenth deal.”

From Smith's Bible Dictionary

William Smith, 1884

[WEIGHTS AND MEASURES AND MEASURES.]