Why Do We Say That?

WHEAT FROM THE CHAFF
In the ancient world grain was hurled into the air using a tool called a winnowing fork. Wind separated the edible part of the grain (wheat) from the lighter, inedible part (chaff). In Matthew 3:12 John the Baptist warned that on judgement day Jesus would separate the wheat from the chaff (good people from evil).

WEASEL WORDS
This phrase is said to come from an old belief that weasels could suck out the inside of an egg leaving its shell in tact.

WENT WEST
Once criminals were hanged in Tyburn - west of London. So if you went west you went to be hanged.

TRUE BLUE
This phrase was originally true as Coventry blue as the dyers in Coventry used a blue dye that lasted and did not wash out easily. However the phrase became shortened.