Brhadarnyaka 1.2.1

 Upanishad says that “immortality is the freedom from being felled by desire and death is the state of being felled by desire.” Bhagavat Gita states in 2.62 that a person faces death when he submits to kama. Brhadarnyaka 1.2.1 says that hunger is death; hunger here means the urge for desiring things, that is the kama. People can easily fall into the alluring kama. When kama takes us over, we lose our identity and meet with death. The cycle thus continues until the relief from death happens, which is known as moksha and that is immortality.