in which he also went and preached to the spirits in prison,
Some interpreters believe that the incident involving the sons of God and the daughters of men (Genesis 6:1-4) is what Peter had in view here. [Note: E.g., Michaels, pp. 206-13.] But there are some problems with this theory. First, this incident evidently did not take place during the construction of the ark but before construction began. Second, it is improbable that the "sons of God" were angels. [Note: See Allen P. Ross, Creation and Blessing, pp. 181-83.] Compare also Jesus’ implication that angels do not procreate in Matthew 22:30. Nevertheless these "spirits" could still be angels. If they are fallen angels, Peter may have meant that after Jesus Christ arose He announced to them that their doom was now sure. He may have done this either by His resurrection itself or by some special announcement to them.