What is the authenticity of adding "for a specified term" to verse 24 of Surat An-Nisa, and was this phrase found in other Mushafs?

The recitation "until a specified term" is not from the widely transmitted recitations (Qira'at Mutawatirah); rather, it is abrogated, because temporary marriage (Mut'ah) was permitted at the beginning of Islam, then it was forbidden permanently until the Day of Judgment. The verse refers to marriage (Nikah) and not temporary marriage (Nikah al-Mut'ah), as indicated by its Quranic context.