We see the chiyuv of “onah” varies from person to person (in halacha) in terms of what their profession was. “Onas Talmud Chacham” — the obligation of Torah scholars — is from Shabbos night to Shabbos night. Many understand this to be because it’s a matter of kedusha yeserah (special holiness) for a Talmud Chacham to only be with his wife once a week and that day is Shabbos.
However I want to ask really the idea of “onas talmud chacham” was a technical one (just like the other people and their chiyuv) in that that talmud chacham is away learning and only comes home once a week on Shabbos (we see there is a chiyuv oneh that is even more than a week apart.) I realize people take it to mean and inyun of kedusha yesera not to be osek in tashmish so much, however is the makor for this and reason really because of the technical aspect or is the whole reason because of kedusha yesera and nothing else?
Answer:
The (Kesubos 62), followed by the Magen Avraham (240:3) and other authorities, explains that the reason for this halachah is that Torah scholars are busy at night with Torah study, and are therefore not free for fulfilling mitzvah onah. The Rambam (30:14) writes that the reason why Chazal fixed the weekly onah on Shabbos is because of Oneg Shabbos.
The Zohar (Yisro 89) adds that there is a special inyan of zivug on Shabbos, to bring down souls on Shabbos.
I do not know a source for the idea that the halachah is based on the need for Torah scholars to minimize their occupation with tashmish — though this idea does appear in the sugya of Berachos concerning the enactment of Ezra for ba’alei keri.
Best wishes.
