This use of blood signified that the priests would obediently do their best to carry out their duties.
وَرَمَزَ ذٰلِكَ إِلَى أَنَّ ٱلْكَهَنَةَ سَيَبْذُلُونَ قُصَارَى جُهْدِهِمْ لِيُتَمِّمُوا وَاجِبَاتِهِمْ بِكُلِّ طَاعَةٍ .‏