vrAtya-kANDa of atharvaveda
The opening of the vrAtya-kANDa of the atharvaveda has elements that have continued to find expression through the history of the shaiva tradition. Here the prAjapatya & aindra flavors of the religion are incorporated within the early shaiva framework of the vrata.
व्रात्य आसीद् ईयमान एव स प्रजापति सम् ऐरयत् ॥
स प्रजापतिः सुवर्णम् आत्मन्न् अपश्यत् तत् प्राजनयत् ॥
तद् एकम् अभवत् तल् ललामम् अभवत् तन् महद् अभवत् तज् ज्येष्ठम् अभवत् तद् ब्रह्माभवत् तत् तपोऽभवत् तत् सत्यम् अभवत् तेन प्राजायत ॥
सोऽवर्धत स महान् अभवत् स महादेवो ऽभवत् ॥
स देवानाम् ईशां पर्य ऐत् स ईशानो ऽभवत् ॥
स एकव्रात्योऽभवत् स धनुर् आदत्त तद् एवेन्द्रधनुः ॥
नीलम् अस्योदरं लोहितं पृष्ठम् ॥
नीलेनैवाप्रियं भ्रातृव्यं प्रोर्णोति लोहितेन द्विषन्तं विध्यतीति ब्रह्मवादिनो वदन्ति ॥There was verily a roaming Vrātya. He animated Prajāpati. Prajāpati beheld gold in his self and engendered it. That became the one; that became one with distinguishing marks; that became great; that became the foremost; that became the brahman; that became heat, that became the truth; by that he was born. He grew, he became great, he became Mahādeva. He attained the lordship of the Gods. He became Īśāna. He became the sole Vrātya. He held a bow, verily that bow of Indra. His belly is blue, his back is red. With the blue he envelops a detested rival, with red he pierces the one who hates him: so say the speaker of brahman.
- shaunaka vulgate
The primal vrAtya is to be understood as rudra himself & when he manifests specifically as nIlalohita-rudra who in the paurANika tradition beheads the 5th head of prajApati. But again note the verb sam-Ir, which is used to indicate the primal vrAtya (rudra) animating prajApati. The same root is behind a name of vAyu; also note its use in the taittirIya-shruti to describe a comparable activity of vAyu: वायुर् नक्षत्रम् अभ्येति निष्ट्याम् । तिग्मशृङ्गो वृषभो रोरुवाणः । समीरयन् भुवना मातरिश्वा । अप द्वेषाँसि नुदताम् अरातीः ॥
This again points to that old connection between vAyu-vAta & the rudra class deity that is presented explicitly in the Iranic world.
व्रात्यो वा इदम् अग्र आसीद्
ईयमान एव स प्रजापति सम् ऐरयत् ॥
स प्रजापतिर् आत्मनः सुपर्णम् अपश्यत् ॥तद् एकम् अभवत्
तल् ललामम् अभवत्
तन् महद् अभवत्
तज् ज्येष्ठम् अभवत् ॥
तद् सत्यम् अभवत्
तद् ब्रह्माभवत्
तेन प्राजायत ॥सो ऽवर्धत
स महान् अभवत्
स महादेवो ऽभवत्
स ईषानो ऽभवत्
स देवानाम् ईशां गच्छेत्
स देवानाम् एकव्रात्यो ऽभवत् ॥स धनुरादत्त
तद् इन्द्रधनुर् अभवत् ॥
नीलम् अस्योदरं लोहितमस्य पृष्ठम् ॥
नीलेनाप्रियं भ्रातृव्यं प्रोर्णोति लोहितेन द्विषन्तं विध्यतीति ब्रह्मवादिनो वदन्ति ॥There was verily a roaming Vrātya. He animated Prajāpati. Prajapati beheld gold in his self and engendered it. That became the one; that became one with distinguishing marks; that became great; that became the foremost; that became the brahman; that became heat, that became the truth; by that he was born. He grew, he became great, he became Mahādeva. He attained the lordship of the Gods. He became Īsāna. He became the sole Vrātya. He held a bow, verily that bow of Indra. His belly is blue, his back is red. With the blue he envelops a detested rival, with red he pierces the one who hates him: so say the speakers of brahman.
- paippalAda
Also, the use of the name IshAna is something that presages the pa~nchabrahma system where that face is placed at the top. As this vrAtya of the gods he is seen as encompassing them
vrAtya in jaiminIya tradition
The earliest expression shaiva-mata (not just the worship of rudra) is seen in the vrata of the vrAtya, a ritual widely recorded in vaidika tradition.
अथैते व्रात्यस्तोमाः । दिव्या वै व्रात्या; व्रात्याम् अधावयन् बुधेन स्थपतिना । त एते व्रात्या आर्चन्न् इमं वैव यो ऽयं पवत ईशानं वा देवम् ।
Now (we shall expound these vrātya songs. The vrātya-s were verily divine. With Budha as their leader they ran after the vrātya-s. They, i.e., these vrātya-s, worshiped him, indeed he who blows here or the god īśāna.
This is the opening of the vrata section of the sAmaveda as specified by the jaiminIya brAhmaNa. A key point to note is the verb pavate, which should be understood as ‘blows’. This links him vAyu-vAta & explains why the non-Zoroastrian Iranic tradition worshipped vAyu-vAta as the rudra class deity. It also explains the continuity between the archaic Indian vrata & Iranic rudrian vAyavya tradition as part of a common vrata tradition that spanned domains.
The shaivamata should be understood as having its foundation in this shared Indo-Iranian tradition – in this case the continuity was maintained down to the destruction of the Iranian religion by the marupishAcha-s in Central Asia.