Let him pay attention to his belly and to what he fills it with! Let him remember death and the tribulation of the Hereafter. Whoever seeks the Hereafter abandons the adornment of dunyā (the world). Whoever acts thus has truly felt modesty before Allah. (Tirmidhi, Qiyāma, 24; Musnad, I, 387)
The specific meaning of modesty (ḥayāʾ) is among the ḥāl (spiritual states). This is like the modesty mentioned in the saying transmitted from ʿUthmān: Even when I perform the ritual bath in the dark at home, I become doubled over out of modesty before Allah.
One of the sages said: Whoever speaks about modesty but does not feel modesty before Allah is a hypocrite.
Dhū al-Nūn said: Ḥayāʾ (modesty) is the presence of hayba (awe) in the qalb (the heart) as an effect of the distress caused by the sins you committed against Allah in the past.
Ibn ʿAtāʾ said: The greatest knowledge is hayba and ḥayāʾ. If a person loses hayba and ḥayāʾ, there remains no good in him.
Ḥayāʾ is from iman (faith). Iman is half sabr (patient endurance) and half shukr (gratitude). Allah is al-Ṣabūr (the Most Patient) and al-Shakūr (the Most Grateful). (Bukhari, Iman, 16; Muslim, Iman, 12) Because of this name, the muʾmin (believer) thanks Allah's servants and endures the harm that comes from ignorant servants. (Futūḥāt, IV, 263)
Ḥayāʾ is to show hurma (reverence) to the foundation of love. The first subtlety of ḥayāʾ arises from the knowledge that the servant possesses due to Allah's gaze. The second subtlety arises from the knowledge of proximity (qurbiyya). The third arises from witnessing one's spiritual rank. There is no limit to this. (Rawḍa, 483)
Ḥayāʾ is an effect born from reverence for the foundation of maḥabba (love). Ḥayāʾ is among the characteristics of lovers. It is followed by submission and lowering the head. Dhū al-Nūn said: If we were to abandon modesty before Allah, we would not speak of maḥabba, and we would become intoxicated with love for the world. (Rawḍa, 652)
Ḥayāʾ is to do nothing that would be blameworthy, outwardly or inwardly. (Jāmiʿ, 54)
Ḥayāʾ is of three kinds: The modesty of the common people arises from faults. The modesty of the elect arises from excess. The modesty of the elite of the elect arises from majesty (jalāl). (Jāmiʿ, 61)
A Sufi said: Ḥayāʾ is the presence of hayba in the qalb as an effect of the distress caused by the sins you committed against Allah in the past. (Nabhānī, I, 236)
Ḥayāʾ and uns (intimate friendship with God) roam the qalb. If they find even a little zuhd (asceticism) and waraʿ (scrupulousness) there, they remain; otherwise, in that ḥāl (spiritual state), they depart.
Suhrawardī said: Ḥayāʾ is the submission of the ruh (spirit) and the lowering of the head before the ʿaẓama (majesty) of Allah's manifestations of Jalāl (Majesty). Uns is the delight of the ruh in the kamāl (perfection) of the Jamāl (Beauty) of the Real (al-Ḥaqq). When both are present together, this is the end of desires and the ultimate of iḥsān (spiritual excellences).
Qushayrī said: Ḥayāʾ is the melting of the qalb because Allah is aware of it. I say: Ḥayāʾ is the presence of hayba in the qalb as an effect of the distress caused by the sins you committed against Allah in the past. This is the saying of Dhū al-Nūn. From him is also transmitted: Love (ḥubb) makes one speak; ḥayāʾ makes one silent; fear (khawf) brings sorrow.
Abū Sulaymān Dārānī said: Servants act with four elements: fear (khawf), hope (rajāʾ), reverence (taʿẓīm), and ḥayāʾ. The highest of these degrees is to act with ḥayāʾ, knowing that Allah sees him everywhere, and that he is more ashamed of Allah's favors to him than the disobedient are of their own sins.
Abū Bakr Warrāq said: Sometimes I perform two units of prayer for Allah's pleasure, complete them with the salām, and afterward I feel as guilty in terms of ḥayāʾ as someone returning from theft.
It was said to one of the Sufis: Give me advice! He replied: It is enough as advice for you that Allah sees you! The interlocutor said: What do you command me? He replied: Do not forget that He is aware of you in all your states.
One of the Sufis said: What dominates the qalb of those who feel ḥayāʾ during Allah's gaze upon them is jalāl (majesty) and reverence (taʿẓīm).
There are many kinds of ḥayāʾ. One is the modesty of committing sin, as seen in the example of Adam. When it was said to Adam, "Are you fleeing from Me?" he replied, "No, rather, I am ashamed before You because of the sin I committed."
Another is the modesty of deficiency, as seen in the angels. The angels say, "We glorify and exalt You; we have not worshipped You as You truly deserve."
Another is the modesty of reverence and exaltation, as seen in Isrāfīl. Isrāfīl folded his wings out of ḥayāʾ before Allah.
Another is the modesty of generosity, as seen in the Prophet. Because the Prophet felt ḥayāʾ before his community, he could not say, "Leave the house." (Nabhānī, I, 382)