Jehovah Sets Precedents? An Idea in Germ Form

A dear friend I knew some years ago, now deceased, used to tell me that she felt Jehovah sets precedents (always?) before he acts. I don't remember reading about this concept in WT literature, but it may be there. And frankly, I don't find the idea objectionable and it even seems scriptural. But I need to do more research, find the scriptural basis for believing that Jehovah sets precedents although the organization has written that Jehovah will set a precedent for all time to come, when he destroys Satan, his demons, and other rebels after the test mentioned in Revelation 20:7-10. Maybe Jehovah also set a precedent when he gave his Son to eradicate sin and death. See also Jude 1-7.