Told to explain the tirtha Prabhasa on Balarama's pilgrimage. Daksha's twenty-seven daughters marry Soma; he stays with Rohini. After three complaints and two warnings Daksha curses him with consumption. Sacrifices do not help; plants lose their juice and creatures waste. The gods intercede. Daksha cannot unsay the curse but orders equal treatment of the wives and a bath at the meeting of Sarasvati and ocean, with worship of the God of gods, and fixes a fortnight of waning and a fortnight of waxing. Soma bathes at Prabhasa on the new moon day and shines again; he returns there every new moon. Daksha's parting word: do not slight women or Brahmanas.
Prajapati gives thirty-three daughters to King Soma, who keeps company with Rohini. The others go home angry. Soma follows; Prajapati returns them only after Soma swears to treat them equally. He breaks the oath and illness seizes him: the 'king's illness', also the 'wife's disease'. He approaches the wives respectfully; they ask as their boon that he live with them equally. An oblation to the Adityas frees him. The rite is prescribed for a wasting illness, at the new moon, with the verse 'he is born ever new'.
What is different here:
Thirty-three daughters, father Prajapati, an oath instead of warnings, no curse, no Prabhasa and no Shiva; the wives set the terms and the cure is an offering to the Adityas; the passage is an origin story for a healing rite.
Daksha gives twenty-seven daughters to Chandra, who loves Rohini alone. Daksha entreats him twice, then says he shall waste, and the Moon fades at once. Gods and sages go to Brahma, who sends them to Prabhasa: Chandra is to install Shiva and worship with the Mrityunjaya rite. Chandra prays six months, repeating the mantra ten crore times. Shiva appears, forgives him and rules that he lose a digit daily in the dark fortnight and regain it in the bright. At the gods' request Shiva stays with Uma as Someshvara or Somanatha; the Chandrakunda pool is made; worship there cures consumption.
What is different here:
Shiva, not Daksha, fixes the waning and waxing; Brahma advises; six months of Mrityunjaya worship replace the bath; ends with the founding of the Somnath jyotirlinga and the Chandrakunda.
Sources: The Mahabharata, tr. K. M. Ganguli (1883-96), sections read for the Vedic layer; The Veda of the Black Yajus School (Taittiriya Sanhita), tr. A. B. Keith (1914); Shiva Purana, Kotirudra Samhita chapter 14 (Somanatha), verse translation at vedapath.app; Somnath temple - Wikipedia