The second thing is more unique to this chapter. Provision is made for eating meat away from the sanctuary, slaughtered without the sacrificial system. This is just a practicality - it may be a long way to the place where YHWH has put his name, and the people will want meat. That's fine - Moses is keen that they be able to enjoy God's blessings in the land. They can eat meat apart from sacrifice. But they still can't eat the blood. That is a long-standing prohibition, the rationale for which seems to be most fully unpacked in Leviticus 17. The blood represents the life of the creature, and that has been give to Israel to make atonement - it is for the covering of sin, not for consumption. Blood has a sacred function, symbolising the life of the animal which has been given in exchange for the life of the sinner. Even so-called 'profane slaughter' is linked to the sacrificial system, and the pouring out of the blood on the ground is a reminder that the animal's life stands between the Israelite and death.
Against this background, Jesus says (of the wine which the disciples have just drunk!), "this is my blood of the new covenant". In Holy Communion, we are commanded to not only eat the flesh, but also to drink the blood. Surely significant!
I've long thought that the part of the sacrificial system we ought to look to for parallels with the Eucharist is the meal in the sanctuary. The sacrifice made, the worshippers celebrate their fellowship with God by eating in his presence of precisely the meat of the sacrifice. We Christians eat together in God's presence, feeding on the body of Christ. It is not a sacrifice - the one and only sacrifice has been made - but is a fellowship meal, enjoying together the fruit of the sacrifice.
But if that's right, what does it mean that in contrast with the OT sacrifices we are particularly commanded to take the blood? Somebody has surely done some proper work on this, but a possibility that occurred to me was that the OT sacrifices never could 'transmit' life. The animal life given up made atonement, but did not 'go into' the worshipper and bring new life. There was transfer of guilt to the animal, and vicarious death (all symbolic, of course, of the great sacrifice), but there was no transfer the other way - no life flowing from the animal to the redeemed worshipper. It strikes me that it is this transfer which characterises the various descriptions of the new covenant in the prophets - not just sin washed away, but sinners changed. Is that why we drink of the blood of the new covenant?