28. examine—Greek, "prove" or "test" his own state of mind in respect to Christ's death, and his capability of "discerning the Lord's body" (1Co 11:29, 31). Not auricular confession to a priest, but self-examination is necessary.
so—after due self-examination.
of … of—In 1Co 11:27, where the receiving was unworthily, the expression was, "eat this bread, drink … cup" without "of." Here the "of" implies due circumspection in communicating [Bengel].
let him eat—His self-examination is not in order that he may stay away, but that he may eat, that is, communicate.