Pfeiffer, certainly aware of Grimm's treatment, dates the general sense as it pertains to things to the 14th century, but has gehörig "gehörend, gebührend, ordentlich" (appropriately, proper) as early as possible with 8th century AHD gihorig, later MHG gehoeric "folgsam, gehorchend" (follow-some, obedient). [cf DWDS]
- Different than Pfeiffer, Grimm [cf DWB gehören] had however opined:
4.a) noch jetzt fragt man auf dem lande z. b. ein kind: wem gehörst du? wer sind deine angehörigen? genauer: wer sind deine eltern, wer ist dein vater? eigentlich: wem hast du zu gehorchen? wer gebietet über dich? also auch, was sachlich oft mit gemeint ist: an wen hab ich mich zu wenden, der dich vertritt u. s. w. das musz uralt sein und der ausgangspunkt von allem folgenden, obwol zeugnisse aus alter zeit fehlen, denn auch der herr (s. 5) ist da ursprünglich an der stelle des vaters gedacht, die zugehörigkeit eine weiterbildung des begriffes der angehörigkeit, beide aber auch begrifflich erweitert zur bezeichnung des beiderseitigen verhältnisses überhaupt (s. 5, b).
[bold emphasis mine, translated below]
this [familiar sense of belonging] has to be ages-old and has to be the origin of all the following [articles in the lemma], although whitnesses are missing from old time ...
then follows an argument that only explains why the discussed sense was prior to the following senses (ie. from family relation to feudal, then material), but does not explain why "uralt" were more than hunch. If I had to guess I'd say far spread distribution would be a good indicator.
- Interesting tidbit by the way: "[gehörst an] entsprechend dem ital. è degli (dei) Alighieri o. ähnl.; diesz angehören mit acc., das ursprüngliche, galt noch im 16. jh." [4.b; details on acc. follow in 4.c]
- Grimms seem to confirm the 8th century
- gehör geben, gehorchen, mit dat. (vgl. goth. hausjandan im u. 1, e); ahd. glossiert es parere, obtemperare, obedire, obsequi, z. b.:
stant ûf, quad er, gihôri mir, joh nim thîn betti mit thir.
Otfr. III, 4, 27.
mhd. zwar nicht bezeugt (vgl. für erhören u. 1, c), aber [...not evident in MHG but ...]
I have no clue who ahd. is--who gave the Latin glosses--but I take it to mean OHG in the figurative sense as an unknown OHG author, and gloss- to mean margin-note.
Grimm cites glosses and translates himself for verbs, whereas Pfeiffer glosses adjectives. In sum, the quoted evidence might show a participle (ie. ?belonging mine)
The reference to Gothic, I first thought only pertained to the commanded Dative casus, not the semantics, but 1.e talks about Genitive; sadly, 1.e is nearly incomprehendable to me either because they assumed the reader were familiar with Latin, or because they leave the interpretation up to reader. In that sense, I will do the same.
1.e ursprünglich aber auch mit gen. obj., wie hören (s. d. 3, e), mhd. und schon ahd., alts., goth.: allai þai hausjandans is. Luc. 2, 47, ἀκούοντες αὐτοῦ (neben hausjandan im, ἀκούοντα αὐτῶν v. 46*);*
joh sînero wortoer hôrta filu harto.
Otfr. II, 9, 57;
hôrian ni weldunis gibodskepies (seine botschaft). Hel. 2661,
so ohne zweifel auch gihôrian, vergl. aus Notker bei Graff 4, 1005 z. b. er gehôrte mih dero bete, wo doch der gen. mehr beiläufig ist als nothwendig zum zeitwort gehörend (vgl. 2, a a. e.); aber bei Schmeller 2, 233 (1, 1156), freilich ohne den nachweis, 'gahôrit mîn, mei audit, ist mir gehorsam', […]
that article seems to have to be read in conjunction with the preceding one, that establishes a sense verstehen "understand".
- Further down, we find a sense be in service of the thing, belong to the local court of law. They presume this had developed from the familiar sense, parallel to or follwing the feudal and martial sense.
7) besondere entwickelung erfuhr es überhaupt im rechts- und gemeindeleben und gieng mit der da erhaltenen färbung in den allgemeinen gebrauch über.
Free translation mine: 7. [the word, the concept] took special development overall in law and commons matters, and came from there into all-common use.
[cites of various laws follow, including Habsburger and the Sachsenspiegel]
Importantly, there's no saying when that development happened. There is good reason to assume the law tried to keep up tradition.
Severly, they don't explain the different forms gehören vs gehorchen, as far as I read.
Also, this said nothing about the Norse terms that you promised in the hypothesis.
So I have to stop at that, because I don't in fact see a coherent picture.
The association with to hear is plausible, but precisely because of that it might well be a lexicalized folk etymology obscuring derivation of one sense from a now unrelated word, but supposing irregular shift in both semantics and phonetics means the possibilities are sheer endless. Even if comparison to the unrelated word were the actual folk etymology, any such influence would still be necessary to explain the development, to find which terms were supplanted.
On another note G belangen has judicial significance. Various other words that could be compared, if one were so inclined, are either uncertain (viz e.g. Deutsch), or appear folk etymologic themselves (viz together).