a law unto themselves

The now commonly-used English idiom “Ta law unto themselves” (meaning someone who does whatever they desire, ignoring the rules and regulations) was first coined in 1526 in the English New Testament translation of William Tyndale (in the spelling a lawe vnto them selve). (Source: Crystal 2010, p. 282)

For other idioms in English that were coined by Bible translation, see here.

See also they are a law to themselves.