Sforno on Leviticus 19:31/ספורנו על ויקרא י״ט:ל״א

1Seeing that the seeking out of oracles such as the ov or yidoni for the gentiles is something akin to enquiring about their fate from G’d, and it involves instead of consulting the living G’d consulting the dead or their remains, the Torah prohibits this in the strongest terms saying אל תפנו אל האובות, meaning not only must you not turn toward them, but you must turn your back on them and on any other phenomena similar to them. The Torah does not need to add that no respect or deference must be shown to such phenomena.

2אל תבקשו לטמאה בהם, do not search them out as they would confer spiritual contamination on you. However, the Talmud did permit us to study the manner in which these phenomena are being used when the objective is merely to understand the phenomenon, not to make use of it. [based on Deuteronomy 18,9 as interpreted in Shabbat 75. Ed.]