Dhikr means the tasbeeh of ruku’ and sajdah.
Tashahhud is wajib after the second sajdah of the second rak'at and that of the last rak’at.
Six things are wajib in it. They are:-
1. Reciting shahadatayn. It is ahwat to recite in the following form: Ash-hadu an la ilaha illal-lahu wahdahu la sharika lahu, wa ash-hadu anna Muhammadan ‘abduhu wa rasuluh."
2. Reciting salawat after shahadatayn.
3. Tartib in its sentences as explained above.
5. Reciting tashahhud while remain sitting.
I bear witness that there is no God but Allah; the only One; There is no partner or equal to Him. And I bear witness that Muhammad is His servant and His Apostle. O Lord! May Thy peace be on Muhammad and His descendants.
It is mustahab in tashahhud that the hands of person rest on the thighs. The fingers should remain close to each other pointing towards qibla. Eyes should rest on the lap. The position of sitting for the man and the woman has already been described In the description of sajdah.
Salaam is wajib after the tashahhud of the last rak’at. Four things are wajib in it:
1. Reciting either of these two sentences: "Assalarnu ‘alayna wa ‘ala ‘ibadillahis salihin."(Peace be on us and on all righteous servants of God). "Assalaamu ‘alaykum wa rahmatullahi wa barakatuh." (Peace be on all of you and the mercy of Allah and His blessings).
2. Remain sitting while reciting salaam.
3. Correct pronunciation.
1. Reciting both salaams.
2. Addition of "Assalaarnu alayka ayyuhan Nabiyu wa rahma-tullahi wa barakatuh" (Peace be on thee, O Apostle, and the Mercy of Allah and His Blessings).
3. Saying takbir three times after Salaam.
It is wajib to perform all the acts of prayer in the prescribed sequence. Any change in that sequence will render the prayer invalid, if done intentionally (and in case of a rukn sequence, even unintentionally).
One act of salaat must be followed by the next act immediately. The intervening time between two acts should not be so long as to give the impression that the person concerned is not praying any more.