How do I detect the type of damage whether it was due to a player or a fall?

[lean bison]

world.afterEvents.entityHurt.subscribe(({ hurtEntity, damageSource }) => {

if (
hurtEntity.typeId === "minecraft:zombie"
) {
hurtEntity.runCommandAsync('/say player')
}
});

[crystal lagoon]

define the cause.

damageSource.cause

here's valid damage causes you can use.

https://learn.microsoft.com/en-us/minecraft/creator/scriptapi/minecraft/server/entitydamagecause?view=minecraft-bedrock-stable

and for detecting it was a player hitting, just define the damaging entity as player.
damageSource.damagingEntity.typeId == "minecraft:player

[lean bison]

😘 ty so much man