The concept of Moksha in the famous Mahamrityunjaya mantra
Trayambakam YajAmahe sugandhim Pushtivardhanam | UrvArukam Iva
BandhanAn Mrityor MukshIya mA AmritAt ||
We adore the Father of the three worlds, Trayambaka, bestower of all
sided fragrance of grace, increaser of fullness and strength; May i be
detached from the bondage of death like a ripe cucumber from the stem,
but not from immortality.
Rig Veda 7.59.12.
The Seer here seeks Moksha for himself and for others from Lord Shiva.
Concept of Moksha in the Purusha Suktam:
VedAhametam purusham mahAntam (1) Adityavarnam tamasah parastAt (2)
Tam evam vidvAn amrita iha bhavati (3) NAnyah panthAvidyate ayanAya
I have known the mighty Purusha (1) Who is refulgent as the Sun beyond
darkness. (2) Knowing Him thus in this life itself, one transcends
death (3). There is no other path leading to the attainment of
Taitiriya Samhita 3.12.17.
These mantras talk about the only method of liberation and which is knowing the Purusha or knowing the self. And they also say that there are no other ways.