The basic meaning of khushu` is the softness of the heart, its being gentle, still, submissive, broken, and yearning. The Messenger of Allah ﷺ said,
| Of a surety there is a morsel of flesh in the body, if it is sound, the whole body will be sound, but if it is corrupt, the whole body will be corrupt. It is the heart.|
When the heart is humble, so too is the hearing, seeing, head, and face; indeed all the limbs and their actions are humbled, even speech. This is why the Prophet ﷺ would say in his bowing (ruku`),
| My hearing, sight, bones, and marrow are humbled to You,|
another narration has,
| and whatever my foot carries.|
One of the Salaf saw a man fidgeting in his prayer and remarked,
|If the heart of this person was humble, so too would his limbs be. This is reported from Hudhayfah (RA) and Sa`id ibn al-Musayyib, and it is also reported from the Prophet ﷺ but is not authentic.|
Mas`udi reports on the authority of a person who narrated to him that `Ali ibn Abi Talib (RA) said concerning His saying,
| those who are humble in their prayer |
|It refers to the humility of the heart, that you soften your shoulder for a Muslim (praying next to you), and that you do not look here and there in your prayer.|
`Ata´ ibn al-Sa´ib reported on the authority of a person that `Ali (RA) said, Khushu` refers to the humility of the heart and that you do not look left and right.
`Ali ibn Abu Talhah narrated that ibn `Abbas said in commentary to the above verse,
|Those who are fearful and still.|
Ibn Shawdhab narrated that al-Hasan, may Allah have mercy upon him, said,
|Humility had taken root in their hearts so their gazes were lowered and their limbs became subservient.|
Mansur reported that Mujahid said,
|The foundation of khushu` is in the heart and quietude in prayer.|
Layth narrated that Mujahid said,
|Part of it is that the limbs be subservient and the gaze be lowered. When the Muslim would stand for prayer, the fear of his Lord would prevent him from turning left and right. |
`Ata´ al-Khurasani said,
|Khushu` refers to the humility of the heart and the subservience of the limbs.|
|It is the quietude of the servant in his prayer.|
|The khushu` of the heart refers to fear and lowering the gaze in prayer.|
Ibn Abu Nujayh narrated that Mujahid, may Allah have mercy on him, said concerning the words of Allah, Most High,
| and humbling themselves to Us.|
|i.e. being humble and meek (mutawadi`).|
Allah, Most High, has described the earth as having khushu` in his words,
|Among his Signs is that you see the earth laid bare and then when We send down water on it, it quivers and swells.|
The meaning of its quivering and swelling is that its bareness and stillness (khushu`) has been removed and in its stead raised is placed (vegetation). This then shows that the khushu` that it had was stillness, lowness, and lack of growth. The same applies to the heart: when it has khushu`, its base desires and thoughts arising from the following of carnal lusts are laid to rest, and it breaks and submits to Allah, Mighty and Magnificent. Khushu` replaces the hearts remoteness, haughtiness, arrogance, and lordliness. When it settles in the heart, the limbs, organs, and motions even the voice are stilled. Allah, Most High, has stated that voices have khushu` in His words,
|Voices will be humbled before the All-Merciful and nothing but a whisper will be heard.|
The humility of voices refers to their being stilled and quieted after being clamorous.
In a similar vein, Allah has described the faces and sight of the disbelievers with khushu` on the Day of Rising. This then proves that all of these limbs can have khushu`.
 Bukhari #52-2051 and Muslim #1599
 Muslim #771 on the authority of `Ali.
 Ahmad #960 on the authority of `Ali and it was declared sahih by ibn Khuzaymah #607
 Ibn Nasr al-Marwazi, Ta`dhim Qadr al-Salah #150 with a da`if isnad
 Marwazi #151 and ibn al-Mubarak, al-Zuhd #419 with a da`if isnad.
 It was ruled mawdù` by Albani, al-Da`ifah #110 and al-Irwa #373
 al-Muiminun (23): 2
 Waki`, al-Zuhd #328, ibn al-Mubarak, al-Zuhd #1148 with a da`if isnad. Suyuti, al-Durr al-Manthùr, vol. 10. pg. 557 records that ibn `Umar said in commentary to the verse, When they stood for prayer, they faced forward in their prayer, they lowered their gaze to the place of prostration, and they knew that Allah had turned to them and so they did not look left or right.
 Tabari, vol. 17. pg. 3.
 Tabari, vol. 17, pg. 8
 i.e. standing in devout obedience (qunut)
 Marwazi, Ta`dhim Qadr al-Salah #138
 Tabari, vol. 17. pg. 3 and Marwazi, Ta`dhim Qadr al-Salah #141. The same is recorded by ibn al-Mubarak, al-Zuhd #169-1149 on the authority of Mujahid.
 Tabari, vol. 17, pg. 10
 al-Anbiya´ (21): 90
 Suyuti, al-Durr, vol. 10, pg. 369 and he references it to ibn Abi Shaybah, `Abd ibn Humayd, ibn al-Mundhir, and ibn Abi Hatim.
 Fussilat (41): 39
 Ta Ha (20): 108
 as stated by ibn `Abbas and recorded by Suyù³i, al-Durr, vol. 10, pg. 242 and he references it to ibn al-Mundhir and ibn Abi Hatim.
 cf. al-Ghashiyah (88): 2, al-Qamar (54): 7, al-Qalam (68): 43, and al-Ma`arij (70): 44
 Refer to Appendix 1 for a further discussion on the meaning and import of khushù`.
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