‘Nasadiya Sukta’ occurs in the 10th Mandala of Rigveda (10.129.1-7). This hymn is very peculiar in many respects. Many thinkers have opined that, the philosophical speculations started, when man began to suspect the efficacy of his own senses. He doubted that his senses are not capable to understand the true character of the experimental world. At this point, man started to ask questions to himself. This is considered as the first step of philosophical speculation, which later, lead to the development of robust thought streams.
Nasadiya Sukta in Sanskrit:-
नासदासीन्नो सदासीत्तदानीं नासीद्रजो नो व्योमा परो यत् |
किमावरीवः कुह कस्य शर्मन्नम्भः किमासीद्गहनं गभीरम् ॥ १॥
न मृत्युरासीदमृतं न तर्हि न रात्र्या अह्न आसीत्प्रकेतः |
आनीदवातं स्वधया तदेकं तस्माद्धान्यन्न परः किञ्चनास ॥२॥
तम आसीत्तमसा गूहळमग्रे प्रकेतं सलिलं सर्वाऽइदम् |
तुच्छ्येनाभ्वपिहितं यदासीत्तपसस्तन्महिनाजायतैकम् ॥३॥
कामस्तदग्रे समवर्तताधि मनसो रेतः प्रथमं यदासीत् |
सतो बन्धुमसति निरविन्दन्हृदि प्रतीष्या कवयो मनीषा ॥४॥
तिरश्चीनो विततो रश्मिरेषामधः स्विदासीदुपरि स्विदासीत् |
रेतोधा आसन्महिमान आसन्त्स्वधा अवस्तात्प्रयतिः परस्तात् ॥५॥
को अद्धा वेद क इह प्र वोचत्कुत आजाता कुत इयं विसृष्टिः |
अर्वाग्देवा अस्य विसर्जनेनाथा को वेद यत आबभूव ॥६॥
इयं विसृष्टिर्यत आबभूव यदि वा दधे यदि वा न |
यो अस्याध्यक्षः परमे व्योमन्त्सो अङ्ग वेद यदि वा न वेद ॥७॥
Who really knows, and who can swear,
How creation came, when or where!
Even gods came after creation’s day,
Who really knows, who can truly say
When and how did creation start?
Did He do it? Or did He not?
Only He, up there, knows, maybe;
Or perhaps, not even He.
— Rig Veda 10.129.1-7
In Nasadiya Sukta, the sage doubts the abilities of his senses, and the knowledge that he gathered through the operation of senses. He is convinced of the relative character of the wordily existence and then, ask questions regarding the Ultimate Reality. He wish to know more about the Ultimate Reality. Here we get a hint that, to attain Moskha, one must knew/realize this Reality.