2 occurrences in 2 dictionaries

Reference: Spirits In Prison

Fausets

1Pe 3:18-19. The argument is, Be not afraid (1Pe 3:14,17) of suffering for well doing even unto death, for death in the flesh leads to life in the spirit as in Christ's case, who was put to death in the flesh but quickened in spirit (i.e. in virtue of His divine nature: Ro 1:3-4; 1Co 15:45; 2Co 13:4) in which (as distinguished from in person) He went in the person of Noah (compare 1Pe 1:11 "a preacher of righteousness" (2Pe 2:5; He went not locally but as Eph 2:17, "He came and preached peace," namely, by His ministers) and preached unto the spirits in prison, namely, the antediluvian unbelievers; their bodies seemed free, but their spirits were in prison (Ps 141:9) and they like "prisoners shut up in the prison" just as the fallen are judicially regarded as in chains of darkness, though for a time at large on the earth (2Pe 2:4; Isa 24:18,22-23; 61:1; Ge 7:11, referred to in Isa 24:18). "His Spirit" long "strove" with them, but ceased to do so because even the seed of the godly Seth proved "flesh" and quenched the Spirit (Ge 6:3).

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Hastings