Rest the bottom on the floor as compared to resting it on the ankle of the left foot, as one normally does during Athayyat. I was told that this was his common practice.
1. It is Waajib (compulsory) to recite at least three verses (equivalent to 18 alphabets) after Surah Faatiha in the first two Rakaats of the Fardh Salaat and every rakaat of four Rakaat of Sunnats and Nafl Salaat. If one deliberately misses out the recitation of at least three verses, the Salaat will be invalid. If one forgets to recite the three verses, then the validity of the Salaat will depend on making Sajda-e-Sahw. If one makes Sajda-e-Sahw, the only Salaat will be valid.
2. There are two ways of resting the bottom. One is Tawarruk ? that is resting the bottom on the ground. The other is resting on the bottom on the left foot. Both ways are mentioned in the Ahaadith. According to Imaam Abu Hanifa [ra], it is better to rest the bottom on the left foot instead of resting it on the ground. If one is unable to do so, then he may rest his bottom on the ground. Rasulullah [Sallallaahu Alayhi Wasallam] rested his bottom on the ground due to old age. Tawarrul was not the general practise of Rasulullah [Sallallaahu Alayhi Wasallam].
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai