What is the evidence for looking the place of prostration when bowing in rukoo’?

Question

Praise be to Allah.

Firstly:

There are ahaadeeth among the saheeh Sunnahs which mention
the teaching of the Prophet (peace and blessings of Allaah be upon him)
concerning looking at the place of prostration during prayer. These, in
general, include all the parts of the prayer, and perhaps these texts are
the ones that were quoted by the scholars of the Standing Committee and
quoted by them in the answer to question no.
8580. These texts include the
following:

Ibn Hibbaan (4/332) and al-Haakim (1/625) narrated that
‘Aa’ishah said: “The Messenger of Allaah (peace and blessings of Allaah
be upon him) entered the Ka’bah and his gaze did not go beyond the site of
his prostration until he came out.” Classed as saheeh by al-Albaani in
Sifat Salaah al-Nabi (peace and blessings of Allaah be upon him).

With regard to the reports of some of the salaf that were
quoted by ‘Abd al-Razaaq al-San’aani in al-Musannaf, these include
the following:

1 – It was narrated that Abu Qalaabah said: I asked Muslim
ibn Yassaar where should my gaze fall whilst I am praying? He said: If it
falls where you prostrate, that is good.

2 – It was narrated that Ibraaheem al-Nakha’i used to like
for the worshipper not to let his gaze wander beyond the place of
prostration.

3 – It was narrated that Ibn Sireen used to like for a man to
focus his gaze on the place of prostration.

Musannaf ‘Abd al-Razzaaq, 2/163

This is what the scholars of the Standing Committee said is
the view of the majority: Abu Haneefah, al-Shaafa’i and Ahmad. Some of them
made an exception in the case of the tashahhud, when the worshipper should
look at his finger. This is a sound exception, supported by reports in the
saheeh Sunnah.

It was narrated from ‘Abd-Allaah ibn al-Zubayr that when the
Prophet (peace and blessings of Allaah be upon him) “sat for the
Tashahhud, he would place his left hand on his left thigh and point with his
index finger, and would not let his gaze go beyond his finger.”

Narrated by Abu Dawood, 990; al-Nasaa’i, 1275; classed as
saheeh by al-Nawawi in Sharh Muslim. 5/81. He said: The Sunnah is not
to let one’s gaze go beyond the pointing (finger). There is a saheeh hadeeth
concerning this in Sunan Abi Dawood.

Some of the scholars interpreted the verse in which Allaah
says (interpretation of the meaning):

“so turn your face in the direction of Al-Masjid Al-Haraam
(at Makkah)”

[al-Baqarah 2:144]

as meaning that the worshipper should look straight ahead,
not at the place where he prostrates, but this is a less correct view.

Ibn Qudaamah said:

It is mustahabb for the worshipper to fix his gaze on the
place of prostration. Ahmad said – according to the report of Hanbal – :
Proper focus and humility (khushoo’) in prayer means that (the worshipper)
should fix his gaze on the place of prostration, this was narrated from
Muslim ibn Yasaar and Qataadah.

Al-Mughni, 1/370

Secondly:

In the saheeh Sunnah it is narrated that when the worshipper
bows, it is mustahabb for him not to raise his head or his gaze, rather they
should be level with his back. It was narrated that ‘Aa’ishah said: The
Messenger of Allaah (peace and blessings of Allaah be upon him) used to
start his prayer with takbeer (saying Allaahu akbar), then he would recite
al-hamdu Lillaahi Rabb il-‘Aalameen (i.e., al-Faatihah), and when he
bowed he would not raise or lower his head, rather it was somewhere between
the two.”

Narrated by Muslim, 498.

Shaykh Ibn ‘Uthaymeen said, when he was explaining how rukoo’
is to be done, that it is mustahabb for the person who is bowing to keep his
back in a straight line.

He said: With his back straight means that his back should be
kept straight throughout, when going down and when coming up; he should not
arch his back, or bend it in such a way that the middle comes down. Rather
his back should be straight. This is what has been narrated from the Prophet
(peace and blessings of Allaah be upon him). ‘Aa’ishah said: “When he
bowed, he did not either raise or lower his head,” – i.e., it was somewhere
in between the two.

Al-Sharh al-Mumti’, 3/90.