Is it true that Shiva is clearly noted as "Prathama Purusha" in any veda? If yes, please give me the references of it.
I need the Sree rudra suktam reference from agniveer foundation veda pdfs.
First of all Each Veda is divided into four portion Samhita, Brahamnas, Aranyakas and Upanishads which I also discuss in my answer here.
Secondly Lord Shiva is called by the name Rudra in Vedas which I discuss here
and here, along with many other names which I discuss here.
Direct Refrences Regarding Lord Shiva as Purusha from Vedas:
Taittariya Aranyaka is the Aranyaka of Taittariya Shakha of Krishna YajurVeda. We find direct reference for Lord Shiva being Purusha from Taittariya Aranyaka. Taittariya Aranyaka 10.12 states that Rudra is the one who is the first among Gods and who saw Hiranyagarbha being born:
यो देवानां प्रथमं पुरस्ताद्विश्वाधिको रुद्रो महर्षिः ।
हिरण्यगर्भं पश्यत जायमान स नो देवः शुभयास्मृत्या संयुनक्तु ॥ १२॥ (Taittariya Aranyaka 10.12)
He who is the first among the Gods, that Rudra who is the great seer who is higher than the Universe (VishwaAdhik), he is the one who saw Hiranyagarbha being born.
Taittariya Aranyaka 10.24 explicitly states 'Purusho vai Rudraha:' or 'Rudra is the Purusha.' It also explains why Rudra is Purusha as:
सर्वो वै रुद्रस्तस्मै रुद्राय नमो अस्तु । पुरुषो वै रुद्रः
सन्महो नमो नमः । विश्वं भूतं भुवनं चित्रं बहुधा जातं जायमानं चयत् । सर्वो ह्येष रुद्रस्तस्मै रुद्राय नमो अस्तु ॥ कद्रुद्राय प्रचेतसे मीढुष्टमाय तव्यसे । वोचेम शंतम हृदे । सर्वोह्येष रुद्रस्तस्मै रुद्राय नमो अस्तु ॥ (Krishna YajurVeda Taittariya Aranyaka 10.24.1, 10.25.1)
All this verily is Rudra. To Rudra who is such we offer our salutation. We salute again and again that Being, Rudra, who is Purusha. The material universe the created beings and whatever there is manifoldly and profusely created in the past and in the present in the form of the world, all that is indeed this Rudra. Salutations be to Rudra who is such. We sing a hymn that confers on us happiness in the highest degree to Rudra who is worthy of praise, who is endowed with the highest knowledge, who rains objects to the worshippers most excellently, who is more powerful and who is dwelling in the heart. Indeed all this is Rudra. Salutations be to Rudra who is such.
Thus from Taittariya Aranyaka we know Lord Shiva is the one who is the first among the gods, who is Purusha and who saw Hiranyagarbha being born.
Svetasvatara Upanishad is one of the major Upanishad which is associated with Krishna YajurVeda. It's verses are also discussed in Brahma Sutras. It also takes verses from Taittariya Aranyaka, Taittariya Samhita, Sri Rudram, Skambha Suktam etc...
Svetasvatara Upanishad (4.12) also states Lord Rudra is the one who gave birth to Hiranyagarbha in the beginning:
यो देवानां प्रभवश्चोद्भवश्च विश्वाधिपो रुद्रो महर्षिः ।
हिरण्यगर्भं जनयामास पूर्वं स नो बुद्ध्या शुभया संयुनक्तु ॥
He, the creator of the gods and the bestower of their powers, the Support of the universe, Rudra the omniscient, who at the beginning gave birth to Hiranyagarbha− may He endow us with clear intellect!
In 3.11 Svetasvatara Upanishad Rudra is explicitly called Bhagavan Shiva (Sarvavyapi sa Bhagavan Tasmat Sarvagata Shiva). In 3.12 he is called Great Purusha (Mahãn prabhurvai Purusha) and it is stated Flame of Ishana is eternal (Ishano Jyotir Aavyaya). In 3.13 it is stated he is the same Purusha who is of size if thumb seated as self of all beings (Angustha Mãtra Purushãntaratma:). In 3.14 it is stated he is the Purusha of 1000 heads, 1000 eyes and 1000 feets. In 3.15 it is stated he is everything that was, that is and that will be and he is Lord of Immortality and Ishana (Utãmritatwa Ye Ishano):
सहस्रशीर्षा पुरुषः सहस्राक्षः सहस्रपात् ।
स भूमिं विश्वतो वृत्वा अत्यतिष्ठद्दशाङ्गुलम् ॥ १४॥
पुरुष एवेदं सर्वं यद् भूतं यच्च भव्यम् ।
उतामृतत्वस्येशानो यदन्नेनातिरोहति ॥ १५॥
(He is) The Purusha with a thousand heads, a thousand eyes, a thousand feet, compasses the earth on all sides and extends beyond it by ten fingers' breadth. The Purusha alone is all this−what has been and what will be. He is also the Lord of Immortality and of whatever grows by food.
So, there is direct reference in Svetasvatara Upanishad for Lord Shiva being Purusha. Svetasvatara Upanishad (4.21) also prays for Dakshinamurty form (south facing form) to end birth and rebirth cycles:
अजात इत्येवं कश्चिद्भीरुः प्रपद्यते ।
रुद्र यत्ते दक्षिणं मुखं तेन मां पाहि नित्यम् ॥ २१॥
It is because Thou, O Lord, art birthless, that some rare souls, frightened by birth and death, take refuge in Thee. O Rudra, may Thy South facing face protect me for ever!
Shiva Sankalpa Sukta is also a Khila Sukta of RigVeda which I discuss here. Shiva Sankalpa Khila Sukta also contains direct reference of Lord Shiva being Purusha:
वेदाहमेतं पुरुषं महान्तमादित्यवर्णं तमस परस्तात् ।
तस्ये योनि परिपश्यन्ति धीरास्तन्मे मनः शिव संकल्पमस्तु ।।9
This great Purusha of the solar hue, beyond darkness I do know; The wise ones who see its womb and origin do so with the mind. May such my mind be of beautiful and divine resolves, filled with Shiva-thoughts.
यो वै वेद महादेवं परमं पुरुषोत्तमम् ।
यः सर्व यस्य चित्सर्व तन्मे मनः शिवसंकल्पमस्तु ।। 22
It is known that Mahadeva is the highest Purusha. All this is his consciousness, May my mind be filled with Shiva thoughts.
There can be so many other direct references. However there are also many Indirect references from Vedas which matches with Characteristics of Purusha like:
तत उदतिष्ठत् सहस्राक्षः सहस्रपात् (Kaushitki Brahmana RigVeda 6.1.13)
There arose (Rudra) of thousand eyes and thousand feets.
सहस्राक्षाय च शतधन्वने च (Sri Rudram YajurVeda)
He who has 1000 eyes and holds hundreds of bows in his eyes.
मृत्युर्मुक्षिय मामृतात् ।। [RigVeda 7.59.12]
who Gives Moksha and Immortality.
अन्नानां पतये नमः [Sri Rudram Anuvaka 2]
Salutations to him who is Lord of Food.
देवानां हृदयभ्यो। [YajurVeda SriRudram]
who is on the heart of Devas.
तासामीशानो भगवः [Yajurveda Sri Rudram]
who is Bhagavan Ishana.
यो रुद्रो विश्वा भुवना विवेश [YajurVeda 5.5.9]
Rudra who entered the whole world.
इमाविश्वा भुवनानि चक्लृपे तस्मै [Atharvaveda 7.87]
He who created this whole world.
देवा वै रुद्रं स्वर्गं लोकं गतं न व्यजानन्न् आदित्यवर्णं चरन्तन् | [Katha Aranyaka 2.100]
Indeed the deva-s did not recognize Rudra who had entered the heavenly world wandering in Aditya Varnam.
And so on there can be many many references.