Boyd’s Bible Dictionary:
(flax). Used for stately robes (Gen. 41:42); priestly vestments (Ex. 28:42; Lev. 6:10); temple veil (2 Chron. 3:14); choral gowns (2 Chron. 5:12), and ordinary dress. Symbol of purity (Rev. 15:6); of luxury (Luke 16:19).
“Linen” From Concise Bible Dictionary:
Linen
Various Hebrew and Greek words are translated “linen,” and there can be no doubt that linen made of flax was known in ancient Egypt and to the Israelites; but cloths generally are called “linen” whether made of cotton or flax, some being distinguished as “fine linen,” such as was worn by the priests, kings. The word shesh, often translated “fine linen” and “fine twined linen” (for the curtains of the tabernacle, etc.) signifies “whiteness,” and is applicable to both fine linen and cotton (Ex. 26:1,31). Joseph was arrayed in “vestures of fine linen” (Gen. 41:42). The wrappings on the ancient Egyptian mummies were for a long time judged to be cotton, but by the use of the microscope they have been discovered to be linen.
“Wheat” From Concise Bible Dictionary:
Wheat Growing in Israel
This cereal was extensively grown in Palestine; the harvest was in May and June. In the parable it is used by the Lord as representing the children of the kingdom, the fruit of the good seed that He was sowing on the earth, in contrast to the tares, or darnel, which Satan secretly sowed among the good seed.
The Lord Himself, being the second Man “out of heaven,” is compared to the grain of wheat that must have remained alone unless it had died, but which in dying would bring forth much fruit. This clearly shows that there was no union of Christ and natural man by His incarnation alone, and that through the death of Christ the fruit produced by His resurrection is of the same order as Christ Himself (Matt. 13:25-30; John 12:24; 1 Cor. 15:48-49).
There are three or four varieties of Triticum grown in Palestine.
Strong’s Dictionary of Hebrew Words:
Meaning:
from an unused root (of the same form) meaning to bleach, i.e. (intransitive) be white; probably cotton (of some sort)
KJV Usage:
fine (white) linen