In the versions of the Finnish vernacular Ballad of the Death of Bishop Henry (Piispa Henrikin surmavirsi), there are several unclear parts. The part consisting of the Bishop's instructions for his coachman where to hide and from which place to observe his death is one of them.
In one of the versions, the Bishop first mentions a stone as a hiding place, however, immediately realizes its unsuitability. Thereafter he suggests an oak tree (along with a horse in one of the versions).
In diverse versions, there is also a dichotomy between listening and watching. The verse kun ei kilpiä kivessä ('there is no shield in the stone') is clearly an etymologizing adaptation of the folklore verse kirves kilpesty kivehen / kivestä (the axe rebounded from the stone / slid off the stone) from the epic cycle on Väinämöinen.
Putting a stone in contrast with a tree, and transplanting a folklore verse about a stone as an agent of a serious injury into the context of a shield has a symbolic motivation: the medieval Christian symbolism operating with the axiological scale between the inanimate (the stone) and animate (the tree, the horse) matter, and the Christianized part of the Finnish folklore attributing the mere hearing/listening to the devil (Hiisi etc.) and the seeing/watching to God. Thus, the Bishop's instructions might be comprehended in three ways, all of them interconnected with concern for the hagiographic testimony: as an effort for the sake of the witness' survival, as an effort to find the proper place for observation of the sacrifice, and finally as an effort to maintain the proper axiological position to pass on the testimony.