That means not just refusing to eat animal blood, as in blood sausage, but also abstaining from human blood, as in the case of blood transfusions.
Tas nozīmē ne tikai neēst dzīvnieku asinis, kas ir, piemēram, asinsdesās, bet arī sargāties no cilvēku asinīm, ko saņem, piemēram, pārlejot asinis.