"Moreover you should know, Shariputra, the length of life of that Thus Come One and of those people is unlimited." Section Eight began by asking why Amitabha Buddha has the name Amitayus, which now starts to be answered. Shakyamuni Buddha tells his disciple Shariputra (sariputra), "Moreover (punah) you should know (khalu), the length (pramanam?) of life (ayuh) of that (tasya) Thus Come One (tathagatasya) and of those (tesam) people (manusyanam) is unlimited (aparimitam)." The subject of this sentence is ayuhpramanam, nominative singular of the neuter noun pramana "1ength/measure/extent," to which is added the neuter noun ayus "life/duration of life," ayuh before the p- of pramana when put into compound to make the compound noun ayuhpramana "length of life." Dependent on the subject are tasya tathtagatasya, genitive singular masculine, and tesam manusyanam, genitive plural masculine. No verb "is" is expressed, but simply the perfect passive participle aparimita "unmeasured/unlimited (privative prefix a- "un-", prefix pari- "around," and root û ma- "measure." The participle is used as an adjective modifying ayuhpramanam. Since the genitive case denotes possession, this amounts to saying, "That Thus Come One and those people have a duration of life which is unmeasured, limitless." Are you able to tell from this much why that Buddha is called Amitayus?