Asalam o alikum, shiekh. i know that imam ahmad bin hanble r.a give choice to the person reguarding placing hand on chest after ruku but my quetion is which hanbali fuqaha of the past not contamprary adopt the veiw of placing hands on chest after ruku? jazakallah

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallAllaahu ʻalayhi wa sallam, is His Slave and Messenger.

You should know first that Imaam Ahmad's position was that it is disliked to place the hands on the chest. Abu Daawood wrote, “I heard him (Imaam Ahmad) say that placing the hands on the chest is disliked.” [Al-Masaa’il]

According to Imaam Ahmad, the right hand is to be placed on the left below the navel, as is the standard view of the School. Another view reported about Imaam Ahmad is that the hands should be placed above the navel and below the chest; a third view reported from him says that the worshipper has the choice to place the hands either above or below the navel. Imaam Ibn Qudaamah said:

“The hands should be placed below the navel as it was related about ʻAli that the Sunnah of the Prophet, sallallaahu ʻalayhi wa sallam, is to place one hand over the other in the prayer below the navel. [Abu Daawood] Another report suggests that the hands should be placed above the navel and a third suggests that the worshipper has the choice to place the hands either above or below the navel.” [Al-Kaafi]

It is true as you mentioned that the Hanbalis maintained that the worshipper has the choice to place the hands either above or below the navel after Rukoo‘ (bowing), Al-Mardaawi said:

“Imaam Ahmad ibn Hanbal held that the worshipper has the choice to release the hands to the side of the body or to place the right hand over the left (after rising from the Rukoo‘).” [Al-Insaaf]

As for the view held by early Hanbalis, Burhaan Ad-Deen ibn Muflih  said in his book An-Nukat ʻala Al-Muharrar that Ibn Hamdaan, the author of Ar-Ri‘aayah, said that the difference of opinion concerning this is similar to that concerning the placement of the hands after Takbeerat Al-Ihraam (the opening Takbeer). In the Sunnah, the right hand should be placed over the left one. The difference of opinion relates to where the joined hands should be placed – whether they should be placed above or below the navel or whether the worshipper has the choice to do either. An-Nukat ʻala Al-Muharrar reads,

“He (Imaam Ahmad) did not mention any judgment on where the hands should be placed after rising from the Rukoo‘. He  said that the worshipper has the choice to leave the hands by the side of the body or to place the right hand over the left one … Ibn Hamdaan said in his book Ar-Ri‘aayah that the difference of opinion concerning this is similar to that concerning the position of the hands after Takbeerat Al-Ihraam.”

Allaah Knows best.