Adam Clarke on 1 Kings 18:28

They cried aloud - The poor fools acted as they were bidden.

And cut themselves after their manner - This was done according to the rites of that barbarous religion; if the blood of the bullock would not move him they thought their own blood might; and with it they smeared themselves and their sacrifice. This was not only the custom of the idolatrous Israelites, but of the Syrians, Persians, Greeks, Indians, and in short of all the heathen world.