Adverb Clauses of Purpose

Adverb clauses of purpose are introduced by the subordinating conjunctions so that,
in order that and lest. (In order that and lest are used in a formal style.)
I will give you a map so that you can find the way.
We eat so that we may live.
The UNO was formed in order that countries might discuss world problems better.
He was extra polite to his superiors lest something adverse should be written into his
records.
'Sleep not lest your Lord come in the night.'
The conjunction that occurred in older English:
He drew the sword that he might defend himself.
'Come hither that I may bless thee.'