He that kills an ox is as if he slew a man; he that sacrifices a lamb, as if he cut off a dog's neck; he that offers an oblation…
The reference may be either to murder merely or to human sacrifice; most probably the latter, since every other member of the sentence expresses a religious act. That human sacrifice was actually perpetrated by those spoken of may be safely inferred from Isaiah 57:5
Parallel VersesKJV: He that killeth an ox is as if he slew a man; he that sacrificeth a lamb, as if he cut off a dog's neck; he that offereth an oblation, as if he offered swine's blood; he that burneth incense, as if he blessed an idol. Yea, they have chosen their own ways, and their soul delighteth in their abominations.
WEB: He who kills an ox is as he who kills a man; he who sacrifices a lamb, as he who breaks a dog's neck; he who offers an offering, [as he who offers] pig's blood; he who burns frankincense, as he who blesses an idol. Yes, they have chosen their own ways, and their soul delights in their abominations: