Why tenet rather than habet?
My feeling with those words is that habet mostly refers to actual objects, in a mundane sense (e.g. "I have a fork"), while tenet is more of an abstract "have" (e.g. "I have a belief").
That seems plausible. (I don't know enough to know whether it's correct.) I like Jem's dative construction better than either, I think.
If anyone can do non-wrong Latin, I could use a translation of the following for HPMOR. The original is supposed to be circa 1200.
No rescuer hath the rescuer.
No Lord hath the champion,
no mother and no father,
only nothingness above.