What is "al-Tankees," and is reciting Surat An-Nas then Surat Al-Baqarah considered "al-Tankees"?

The meaning of tankees (reversing the order) in recitation is to recite a surah (definition) that precedes the recited surah in the order of the Mushaf (definition) (the written copy of the Quran). Scholars have differed regarding its ruling, oscillating between makrooh (disliked) and mubah (definition) (permissible), with a preference for abandoning it.

Al-Nawawi transmitted from Iyad the permissibility of reciting a surah before the one recited in the first rak'ah, and its dislike within a single rak'ah or for someone reciting outside of prayer, while others permitted it.

As for the surahs, some scholars disliked it, based on the hadith (definition) of Ibn Mas'ud, while others did not dislike it due to the differing order of surahs in the Companions' Mushafs and the fact that their arrangement was a matter of ijtihad (definition) (independent reasoning), and because the Prophet, peace and blessings be upon him, recited Surat An-Nisa before Al Imran.

If the worshipper recites Surat An-Nas in the first rak'ah, it is recommended for him to recite the beginning of Al-Baqarah in the second rak'ah, because it is the end of the Mushaf and Al-Baqarah is its beginning.

Furthermore, reciting the beginning of Al-Baqarah after Surat An-Nas is not considered part of the tankees about which there is disagreement.