barley

It is noted that Naomi and Ruth arrive in Bethlehem at the beginning of the barley harvest. Although one might see that only as a marker of time, I sense there may be a deeper significance to this statement as well as the events that result from this time frame.

Barley was a grain that was cultivated both in Egypt (ex 9:31) and Palestine (lev 27:16; deut 8:8; 1 chron 11:13; jer 41:8). It is the hardiest of all the grains; its plants being strong enought to withstand both drought and extreme temperatures. The crop is sown in the autumn, after the early rains and is harvested in time for the passover; starting in April (sometimes in March) before the wheat; sometimes a week before, sometimes a few weeks before.

It's primary use was for "poor man's bread" (jud 7:13; 2 kin 4:42). The account of feeding the five thousand uses 5 barley loaves which were offered by a little boy (john 6:9,13), signifying the spiritual poverty of the crowd. Ground barley was measured and one-tenth of an ephah was given for the wife as an offering (num 5:15). Barley was also used in lieu of or in addition to monetary payments (2 chron 2:10; hos 3:2); to pay tribute taxes (2 chr 27:5); as a standard of measure (lev 27:16; 2 kin 7:1; rev 6:6) and was typically fed to the horses (1 kin 4:28).

The harvested barley is used in the Feast of the Firstfruits since the two fall at the same time. in this aspect, barley represents those who are considered "overcomers." It is important to note that the value of a bushel of barley seed was valued at 50 sheckels of silver (lev 27:16); as the number 50 is highly significant; 50 days for the pentecost, 50 years for jubilee. The value God places in the barley is meant to show a full outpouring of His Spirit on those who are the first to be raised in Christ. Those symbolized by barley will be ones who flourish even in seasons of drought or extreme temperatures between the outpourings of God.

For more information about barley:
Wikipedia
Net Bible
Passover and the Barley Harvest