The origin of phraseological units in the English

Phraseological units may come from the following spheres :

1. From engineering

Ex:to put the plough before the oxen

2. From agro-cultural

3. from sea-travelling business

Ex:to be in low waters

4. from trade and commerce

Ex: into bargain

National customs and traditions

Ex: by hook or by crook

from the words of Greek and Latin classics, from the Bible