“Speak to the birds.” This is an example of God telling His prophets to speak, that is, to prophesy, which is sometimes important in God bringing His Word to pass (see commentary on Hosea 6:5).
“of every kind.” The Hebrew text is literally, “of every wing,” meaning of all the different kinds of birds.
“Gather yourselves from all around.” The Hebrew is more literally, “from every side.” The birds and wild animals that were going to assemble and eat the flesh of all the people who died in the Tribulation and Armageddon were the “guests” who God called to His great sacrifice and feast (cp. Zeph. 1:7; Rev. 19:17-21).
“in order that you may eat flesh and drink blood.” In a culture where family ties were strong and family tombs common, to not have anyone bury your dead body was considered a terrible curse. In fact, many people believed (falsely, but it was a very widely held belief) that a proper burial was important for a comfortable existence in the afterlife. Thus the threat of not being buried but having one’s dead body eaten by animals, birds, and vermin was a horrifying threat of unspeakable loneliness and rejection, both on this earth and in the afterlife (see commentary on Jer. 14:16).