What is the biblical basis for lifetime eldership?

Some churches who appoint elders do so for a term (3 years is typical from what I have seen). Other churches ordain elders for life. Is there a Biblical basis for ordaining elders for life? This is a follow on to my question about [term eldership.](https://christianity.stackexchange.com/questions/7573/what-is-the-biblical-basis-for-term-eldership)