We're going to find, as SeaBass just pointed out, that forever in the old testament is not the same as the new.
Pertual, for ever, everlasting, etc., are pretty much derivaties of OWLAM in the hebrew.
Look at this scripture in Leviticus 3:17 " [SUP] [/SUP]It shall be a perpetual statute for your generations throughout all your dwellings, that ye eat neither fat nor blood."
Now when Peter saw the sheet in the vision in Acts 10, God told him not to call something He had cleansed, common. Most people don't eat/drink blood today, but fat is a regular part of our diet. This statute lasted in perpetuity, which in this case was until Christ's ministry.