Wording of the Tashahud in the 2nd and 4th Rakat

Wa alaykum as salaam wa rahma!

Thank you for your question! According to the Taaj al-Mudhhab, the wajib of the tashahhud is:
أَشْهَدُ أَنْ لَا إلَهَ إلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ

The other portion of the tashahhud is sunnah. It is similarly repeated in both 2nd and 4th units wit the exception that the prayers upon the Prophet and his Progeny is recited in the 4th for a four unit prayer, 3rd in a three-unit prayer and 2nd in a two unit prayer.

And Allah knows best!

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