When I first read that, I wasn't sure if there was a scriptural rule against it, or if it was something cultural/traditional.
But I found this page: http://www.al-islam.org/laws/najisthings.html which lists things which are considered unclean ("najis"). Blood is among them, and it says "Writing the holy Qur'an with najis ink, even one letter of it, amounts to making it najis. And if written, it should be erased or washed off. "
no subject
"It was wrong to do what he did, to write it in blood," says Sheikh Samarrai. "It is haraam [forbidden]."
no subject
But I found this page: http://www.al-islam.org/laws/najisthings.html
which lists things which are considered unclean ("najis"). Blood is among them, and it says "Writing the holy Qur'an with najis ink, even one letter of it, amounts to making it najis. And if written, it should be erased or washed off. "