Samskritam letters originated from the sound of Damaru as played by Lord Nataraja. There is a Shloka in नन्दिकेशरकृत काशिका ग्रन्थ which mentions from the sound of Damaru Samskritam letters origin , which goes as follows:
नृत्तावसाने नटराजराजो ननाद ढक्कां नवपञ्चवारम् । उद्धर्तुकामः सनकादिसिद्धान् एतद्विमर्शे शिवसूत्रजालम् ॥
As per the above Shloka Lord Nataraja (Shiva) after finishing the dance (Tandava), played the Damaru Navpanch (fourteen) times for the Sankadi Rishis for their Siddhi and salvation of desire (fulfillment). In this way the plexus of fourteen Shivasutras (alphabet) appeared.
The Sound of Damaru as played by Lord Nataraja , Navpanch ( fourteen ) times manifested 14 Maheshwar Sutra .
So the origin of Samskritam letters is these 14 Maheshwar Sutra .
MAHESHWAR SUTRA also known as Shiv sutra is the foundation of entire Vedic scriptures . As per Paniniya Shiksha Shloka 57 we come to know that Maharshi Panini have used these 14 Maheshwar Sutra to compose the unparalleled and master–mind work on Vyakaran Vedanga called Ashtadhyayi (Eight-chapters)
येनाक्षरसमाम्नायमधिगम्य महेश्वरात् ।
कृत्स्नं व्याकरणं प्रोक्तं तस्मै पाणिनये नमः ॥ ५७पाणिनीय शिक्षा
Maharshi Panini uses Maheshwar Sutras in Ashtadhyayi to form “Pratyahar” so Maheshwar Sutra is also known “Pratyahar Sutras.”
9 swar : अ इ उ ऋ ऌ ए ओ ऐ औ
33 Vyanjan : ह य व र ल ञ म ङ ण न झ भ घ ढ ध ज ब ग ड द ख फ छ ठ थ च ट त क प श ष स
Special letters in Samskritam .
In Samskritam “letter or alphabet” is known as वर्ण / varn , so these 14 Maheshwar Sutra are technically Samskritam Varnamala. Varn means letter and mala means sutra . As per Paniniya Shiksha , अयोगवाहा (Ayogwah), यमाः (Yama) , and दुःस्पृष्टः (duhsprshtah) are special varn (letter) that are present in Samskritam Varnamala (these special varn will be explained in future post).