وَكَانُوا يُصِرُّونَAnd were persisting,means, they persisted and did not intend to repent,عَلَى الْحِنثِ الْعَظِيمِin great sin.in disbelief in Allah and claiming that the idols and rivals were gods besides Allah.It means idolatry, according to Ibn Abbas.This is also the meaning reported from Mujahid, Ikrimah, Ad-Dahhak, Qatadah, As-Suddi and others.Allah said,وَكَانُوا يَقُولُونَ أَيِذَا مِتْنَا وَكُنَّا تُرَابًا وَعِظَامًا أَيِنَّا لَمَبْعُوثُونَ