303 OM maha-ashanaaya namaH .
One who consumes everything at the end of kalpaa.
814 OM amRita-vapushhe namaH .
One whose form is deathless, that is, undecaying.
68 OM shreshhThaaya namaH .
(note sh is pronounced as in श and shh is pronounced as ष)
One deserving the highest praise (prashamsA). 'prANo vAva jyeshhThAs cha shreshhThas cha' - prANa alone is the eldest and the greatest (Chhandogya Up5.1.1). The reference here is to the concept of mukhya-prANa. Or being the first cause and thus elder to all, He is jyeshhThah, and being the highest Being excelling others, He is shreshhThah.