Why does the bible never specifically condemn premarital sex?

Most Jewish and Christian scholars define πορνεία (sexual immorality) to include premarital sex. However, where either the old or new testament mention specific sexual immoralities, it's never included. In Leviticus 18 many specific acts are condemned, but not premarital sex. Likewise, Paul spoke specifically of incest in 1 Corinthians 5, adultery and prostitution in 1 Corinthians 6, and homosexuality in Romans 1. If premarital sex is indeed immoral, it is obviously the most prevalent form of immoral sexual acts by far, so then, why doesn't he repeatedly warn against it?