Verily before this, they were at ease.
They insisted on the great blasphemy.
and persisted in the great si
And they persisted in the great violation
And they were persisting/insisting on the sin the great
[but instead of being grateful to God,] engaged constantly in great sins
And were stubborn upon the great sin (of disbelief)
And persisted in extreme sinfulness
And obstinately persisted in great sin (of denying Allah and setting up partners with Him)
But (they) persisted in extreme sinfulness
And were persisting in great sin (joining partners in worship along with Allah, committing murders and other crimes, etc.