( a) What is a codex, and what advantages did it have over a scroll? ( b) When did the codex become widely used by Christians?
فَبَاتَ بِمَقْدُورِ ٱلْقَارِئِ فَتْحُ ٱلْمُجَلَّدِ وَقِرَاءَةُ ٱلنَّصِّ ٱلَّذِي يُرِيدُهُ فِي ٱلْأَسْفَارِ ٱلْمُقَدَّسَةِ .‏