Ezekiel, as a priest, had been accustomed to the strictest abstinence from everything legally impure. Peter felt the same scruple at a similar command (Act 10:14; compare Isa 65:4). Positive precepts, being dependent on a particular command can be set aside at the will of the divine ruler; but moral precepts are everlasting in their obligation because God cannot be inconsistent with His unchanging moral nature.
abominable flesh - literally, “flesh that stank from putridity.” Flesh of animals three days killed was prohibited (Lev 7:17, Lev 7:18; Lev 19:6, Lev 19:7).