Shared ground
Isaiah 18:6 depicts the aftermath of a decisive defeat. The defeated are “left” out in the open with no burial or recovery. Scavenger birds from the mountains and land animals consume what remains. The picture is public, shameful, and complete.
The verse also stretches the scene across time: the birds “summer” on the bodies and the animals “winter” on them. However one takes the timing, the point is that the collapse is not followed by rescue or honor for the dead. It is abandonment.
Where interpretation differs
Who “they” are. Some read “they” as the leaders/forces described in the prior “cutting down” imagery (18:5), focusing on a specific army or ruling class. Others take “they” more broadly as the people identified with that power—an entire defeated host.
How broad “earth/land” is. Some understand “animals of the earth” as “animals of the land,” meaning the local region where the bodies lie. Others hear a broader sound (“earth” as the world), emphasizing the total exposure of the defeat rather than its geography.
How literal the seasons are. Some take summer and winter as a realistic description of bodies left unburied for a long period. Others take the seasonal pair as a way of saying “all year long,” a totality expression that underlines uninterrupted ruin.
Why the disagreement exists
The oracle shifts imagery (from pruning/cutting in 18:5 to corpses in 18:6), and pronouns are not reintroduced with a clear label. Also, the key word often translated “earth” () can mean the whole earth or a particular land, and “summer/winter” can function either as literal time markers or as a compressed way to say “through every season.”
What this passage clearly contributes
This verse contributes a stark description of what divine judgment can look like in history: total defeat, loss of honor, and the removal of ordinary human protections (like burial). Explicitly, it says the dead are abandoned to scavengers and remain so across an extended span of time. By inference from the chapter’s flow (18:5–7), it also intensifies the contrast between human powers being suddenly cut down and the later scene where attention turns to Zion (18:7).