Translation of "weightier" into Arabic

As a child grows older, perhaps he or she can be entrusted with somewhat weightier responsibilities.

وربما يمكن ائتمان الولد على مسؤوليات اثقل نوعا ما وهو يكبر.

The scribes and Pharisees “disregarded the weightier matters of the Law, namely, justice and mercy and faithfulness.”

فَٱلْكَتَبَةُ وَٱلْفَرِّيسِيُّونَ ‹تَجَاهَلُوا أَثْقَلَ مَا فِي ٱلشَّرِيعَةِ، أَيِ ٱلْعَدْلَ وَٱلرَّحْمَةَ وَٱلْأَمَانَةَ›.