Job 16:21

“Oh that one might plead for a man with God, etc.] That is, that one might be appointed and allowed to plead with God on his account; or that he be admitted to plead with God for himself; or however, that there might be a hearing of his case before God, and that he would decide the thing in controversy between him and his friends, when he doubted not but it would be given on his side: as a man [pleadeth] for his neighbour; using great freedom, and powerful arguments, and having no dread of the judge, nor fear of carrying the cause for his neighbour; so Job wishes, that either one for him, or he himself, might be freed from the dread of the divine Majesty, and might be suffered to speak as…”

“one--rather, "He" (God). "Oh, that He would plead for a man (namely, me) against God." Job quaintly says, "God must support me against God; for He makes me to suffer, and He alone knows me to be innocent" [UMBREIT]. So God helped Jacob in wrestling against Himself (compare Job 23:6; Gen 32:25). God in Jesus Christ does plead with God for man (Rom 8:26-27). as a man--literally, "the Son of man." A prefiguring of the advocacy of Jesus Christ--a boon longed for by Job (Job 9:33), though the spiritual pregnancy of his own words, designed for all ages, was but little understood by him (Psa 80:17). for his neighbour--Hebrew, "friend." Job himself (Job 42:8) pleaded as intercessor for his…”

“Oh that one might plead for a man - A more correct rendering of this would be, “Oh that it might be for a man to contend with God;” that is, in a judicial controversy. It is the expression of an earnest desire to carry his cause at once before God, and to be permitted to argue it there. This desire Job had often expressed; see Job 13:3, note; Job 13:18-22, notes. On the grammatical construction of the passage, see Rosenmuller. As a man pleadeth for his neighbour - Hebrew “the son of man;” that is, the offspring of man. Or, rather, as a man contendeth with his neighbor; as one man may carry on a cause with another. He desired to carry his cause directly before God, and to be permitted to…”

“plead: Job 9:34, Job 9:35, Job 13:3, Job 13:22, Job 23:3-7, Job 31:35, Job 40:1-5; Ecc 6:10; Isa 45:9; Rom 9:20 neighbour: or, friend Job 16:22”