The kAthaka grihyasutra, also known as laugAkshi grihyasutra is the household ( grihya ) manual of those who follow any of kAthaka shAkhA of krishna yajur veda. Actually vaishampAyan imparted this yajurveda to katha Acharya , then he imparted his knowledge of yajurveda to 12 shishyAs namely
1) charaka
2) Avhraka
3)bhrAjishthal katha
4) prAchya katha
5) kapishthala katha
6) vArAyanIya
7) chArAyanIya
8) shveta
9) shvetAshavatar
10) Aupamanyava
11) pAtandineya
12) maitrAyana
Then they imparted this to their shishyAs so this formed 12 shAkhAs of katha yajurveda . Hence every shAkhA among 12 shAkhAs is known as kAthaka .kAthak is not name of independent shAkhA but a term used by group of 12 shAkhAs in remembrance of katha Achary. Even in printed text of kAthak samhitA we observe

According to the brahmins of kashmir who have held the rules given in this manual in esteem for a long time ,the author is laugAkshi . kashmirians studied it intensively .
It have two distinct versions for two different branches of krishna yajurveda ( namely caraka shAkhA and cArAnIya ).
1) sa-mantraka kAthakE laugAkshi sutrE caraka grihya sutra
2) sa-mantraka kAthakE laugAkshi sutrE cArAnIya grihya sutra
Among three commentaries ( one bhAshya , two paddhati) two are of sa-mantraka caraka grihyasutra , and one of sa-mantraka-cArAnIya grihyasutra .
The earliest explanatory work is a brief vivararan by Adityadarsana ,in which each sutra is explained separately. brahmanabala wrote a pancika, a detailed treatise of the paddhati style, containing ritual rules and regulations and supplementing the sutra text with additional instructions. Quoting for each chapter first the complete sutra text and subjoining the mantras to his own observations.( these two belongs to sa-mantraka caraka grihyasutra ,)

There is, in the third place, a commentary bhAshya on the sutras and indicated as well as full mantras ( mantrapratika ,sakal pAtha )by devapAla,he commented on a different version i.e. “sa-mantraka-cArAnIya grihyasutra ” in which the sutra text is often preserved but elsewhere replaced by the commentary. Moreover, there are very useful so-called richakas .

kAthak mantra pAtha
kAthak mantra pAtha is collection of mantra which are indicated as mantrapratika in grihya sutra and aren’t found in kAthaka samhitA .These some times also known as kAthaka mantrAdhyaya is additional section found only in commented version by devapAla of this grihya sutra. i.e. in sa-mantraka- cArAnIya grihyasutra .
The major possibility is that, this mantras are either from cArAnIya shAkhA or kalapajA richaks ( mantras of ritualistic origin ) . Some of this mantras are accented ( only with uddAta which is only svara marked in kAthak samhitA , marked as a bar on top of akshara ) and other are not .There are 8 parts of this
kAthaka mantrAdhyaya .
1st part contains a single
mantra without accent , this mantra is not traced in any vedic samhita .
2nd Part consist of jayAdi mantra , it is clear that this mantras are not found in kAthak samhita so they are collected in this section .
3rd Part consists of Adhipatya mantra commonly known as AbhyAtan mantra in yajur vedic tradition.
4th part consist of sarasvatyanuvAka consisting of 21 accented mantras.( they are also not traced anywhere ) devapAla applies this mantras in vivAha samsakAra .
5th Part consists of 5 mantras related to agnimukham.
Last mantra’s half part is traced in kAthak samhita.
6th Part consists of 8 mantras known as kapota sukta in kAthak tradition .
7th Part is longest part consisting of two anuvAka related to srAddha ceremony .
Some mantras in this section are from kAthak samhita.
8th Part consists of 8 mantras known as adabhuda shAnti sukta.
This mantraprashna has collection of mantras which aren’t connected to each other( prakrana pathita mantrA ), so it is also a possibility that this is a small fragment of kAthaka mantra pAtha preserved in devapAla’s commentary . Possibly the original one was quite brief than that of our text. Few accented mantras show that this treaties like that of Apastamba was accented and possess important place in kAthak grihya tradition.
Even till the date Kashmiri brAmhans followes this sutra and perform rituals on behalf of the kAkhaka grihya sutra .
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