'Perpetual' in the Bible

‘Thus says the Lord God, “Because the Philistines have acted revengefully and have taken vengeance [contemptuously] with malice in their hearts to destroy with everlasting hostility and hatred,”

Because you [descendants of Esau] have had an everlasting hatred [for Jacob (Israel)] and you handed over the sons of Israel to the power of the sword at the time of their tragedy, at the time of their final punishment [the Babylonian conquest],

I will make you an everlasting desolation and your cities will not be inhabited. Then you will know [without any doubt] that I am the Lord.

Also you shall provide a grain offering with it morning by morning, one-sixth of an ephah with one-third of a hin of oil to sprinkle on the finely-milled flour. This is a perpetual ordinance for a continual grain offering to the Lord.