Shatpatha Brahmana 2.1.2 gives the details about setting up sacrificial fires under the Krittikas (Pleiades constellation) and mentions something interesting:
He may set up the two fires under the Krittikâs; for they, the Krittikâs, are doubtless Agni's asterism, so that if he sets up his fires under Agni's asterism, (he will bring about) a correspondence (between his fires and the asterism): for this reason he may set up his fires under the Krittikâs.
Moreover, the other lunar asterisms (consist of) one, two, three or four (stars), so that the Krittikâs are the most numerous (of asterisms): hence he thereby obtains an abundance. For this reason he may set up his fires under the Krittikâs.
And again, they do not move away from the eastern quarter, whilst the other asterisms do move from the eastern quarter. Thus his (two fires) are established in the eastern quarter: for this reason he may set up his fires under the Krittikâs.
On the other hand (it is argued) why he should not set up the fires under the Krittikâs. Originally, namely, the latter were the wives of the Bears (riksha); for the seven Rishis were in former times called the Rikshas (bears). They were, however, precluded from intercourse (with their husbands), for the latter, the seven Rishis, rise in the north, and they (the Krittikâs) in the east. Now it is a misfortune for one to be precluded from intercourse (with his wife): he should therefore not set up his fires under the Krittikâs, lest he should thereby be precluded from intercourse.
But he may nevertheless set up (his fire under the Krittikâs); for Agni doubtless is their mate, and it is with Agni that they have intercourse: for this reason he may set up (the fire under the Krittikâs).
I am aware of the story of Agni's wife Svaha impersonating the wives of Saptarishis one by one and he cohabiting with theses different forms so I am presuming that the last verse refers to that relationship. But I want to know about the previous verse that says their husbands were not permitted to have intercourse with them. They must have had conjugal relations later for they all have children so probably this restriction was for some time.
I want to know why were the Saptarishis precluded from having marital relations with their own wives? Was it just because of distance as mentioned in the verse or does it have some other story behind it?
