أَشْهَدُ أَنْ لَّا إِلَهَ إِلَّا اللهُ وَحْدَهُ لاَ شَرِيكَ لَهُ، وَأَشْهَدُ أَنَّ مُحَمَّداً عَبْدُهُ وَرَسُولُهُ

I bear witness that none has the right to be worshipped except Allāh, Alone, without partner, and I bear witness that Muḥammad is His slave and Messenger.

Reference: Muslim (#234, 1/209).