Dhikr in Bowing and Prostration
Question :

Is any dhikr permissible in bowing and prostration?

Answer :

It is sufficient in the bowing position to recite "Subhana Rabbiyal-Adheem wa bi-Hamdih", or "Subhanallah" three times. It is also sufficient to recite any sort of "dhikr" that consists of praising Allah, like "Alhamdulillah" thrice, reciting Takbir thrice or reciting "La Ilaha Illallah" thrice, provided that the said is equivalent to "Subhanallah" three times. The same applies to prostration except that "Subhana Rabbiyal-Aala wa bi-Hamdih" is to be recited instead of "Subhana Rabbiyal-Adheem wa bi-Hamdih". But, it is not sufficient to recite, "Subhana Rabbiyal-Aala wa bi-Hamdih" in bowing, nor is it sufficient to recite, "Subhana Rabbiyal-Adheem wa bi-Hamdih" in prostration.

The Voice of the Dhikr
Question :

Do we have to recite the Dhikr in bowing or prostration in an audible voice or in an inaudible voice, depending on the prayer?

Answer :

It is permissible to recite the dhikr in the prostration in any level of voice during any prayers.

Reciting Dua in Ruku or Sujood
Question :

Can a supplication be recited in the ruku or prostration of an obligatory or recommended prayer?

Answer :

It is permissible to recite any supplication. It has been recommended in some narrations to recite the salawat after the obligatory recitation of the prostration and the bowing.

Steadiness in Bowing
Question :

I understand that it is a condition of prayer that the body should be steady before reciting Dhikr in the bowing, and scholars have emphasized this point saying that prayer is void without this. What exactly is meant by steadiness?

Answer :

There is nothing more required than being steady in the conventional and natural sense.

Reciting Salawat
Question :

Is reciting salawat once sufficient as a thikr in Ruku and Sujud? Or must it be accompanied by another thikr?

Answer :

Reciting only the salawat in bowing or in prostration is not sufficient.

Saying "Subhanallah" in Bowing and Prostration
Question :

Is it permissible to say "Subhanallah" three times in the bowing (Ruku) or prostration (Sujood)? Is reciting it once sufficient?

Answer :

This should be recited three times in the bowing and prostration, and reciting it once is not sufficient.

Recommended Dhikr of Bowing
Question :

Is reciting "Sami'Allahu Liman Hamidah" obligatory after bowing (ruku) in recommended or obligatory prayers?

Answer :

No, it is not obligatory; rather, it is recommended in all prayers.