مسائل المنتخبه (Articles Of Islamic Acts) - الخوئي، السيد أبوالقاسم - الصفحة ٢٢٤ - RUKU (BOWING)

And after reciting Surah Qul huwallahu Ahad he should say, "Kazalikaahu Rabbi" once, twice or thrice or KazalikallahuRabana" thrice. And after reciting the surah he should wait a little and then pronounce the Takbir before bowing or recite qunut
١٠٢٧. It is recommended that in all the prayers one should recite Surah Qadr in the first unit and Surah Ikhlas in the second unit.
١٠٢٨. It is abominable that one may not recite Surah Ikhlas even in one of the daily prayers.
١٠٢٩. It is abominable to recite Surah Ikhlas in one breath.
١٠٣٠. It is abominable to recite in the second unit the same surah which he has recited in the first unit However, if one recites surah Ikhlas in both the units it is not abominable.

RUKU (BOWING)
١٠٣١. In every unit the person offering prayers should, after reciting the surahs (Qirat) bow to such an extent that he may be able to rest his hands on his Knees.This act is called bowing.
١٠٣٢. If the person offering prayers bows to the extent of bowing there is no harm even if he does not place his hands on his knees.
١٠٣٣. If a person performs bowing in an unusual manner e.g. if he bends towards left or right, his bowing is not in order even though his hands may reach his knees.
١٠٣٤. Bending oneself should be with the object of bowing. Hence, if a person bends for some other purpose (e.g. to kill an insect) he cannot reckon it to bebowing. Then he should stand up and should bend again for bowing. Hence bowing does not increase because of this action. and the prayers is not nullified.
١٠٣٥. If there is a difference between hands and Knees of a