The Meaning of Awe
Wara` linguistically: is having reservations towards a thing. One who is wari` - with a kasrah - is the pious one who holds reservations about a matter. Originally, wara` is leaving off the unlawful and being reserved therefrom, then it was used to mean the same thing but with what is permissible and lawful.  Lisan al-`Arab, Ibn Manzur (8/388); Taj al-`Arus, al-Zabidi (22/313).
Wara` technically: is avoiding doubtful matters, whether by actively avoiding it or doing something which makes one far from doubt. It is used to mean piety as well, which is leaving off unquestionable unlawful matters.  al-Kulliyyat, al-Kafawi (p. 944). The Difference between Awe and Asceticism (Zuhd)
Asceticism is leaving what will not benefit one in the next life, while having awe makes one leave off what one fears may harm him therein.  al-Fawa’id, Ibn al-Qayyim (p. 181). The Virtue of Having Awe and Encouragement towards it in the Sunnah
❖ Sa`d ibn Abi Waqqas, Allah be pleased with him, narrated from the Prophet ﷺ that he said: “The virtue of knowledge is more beloved to me than the virtue of worship, and the best of your religion is having awe.”  Reported by al-Hakim (314) and al-Bayhaqi in al-Adab (830). al-Albani authenticated it in Sahih al-Jami`(4214).
❖ Abu Hurayrah, Allah be pleased with him, said: “Allah’s Messenger ﷺ said: ‘Abu Hurayrah, have awe and you will be the most worshipping of people.’”  Reported by Ibn Majah (4217) and al-Bayhaqi in Shu`ab al-Iman (5750). al-Busiri graded it as sound in Misbah al-Zujajah (4/240), and al-Albani authenticated it in Sahih Sunan Ibn Majah (4217). Quotes of the Predecessors and Scholars on Awe
❖ Abu al-Darda’ said: “Perfect piety is that the slave is mindful of Allah, until he does so with what is an atom’s worth of a thing, even leaving off some of what he views as lawful fearing that it may be unlawful, as a barrier between him and it.”  Reported by Ibn al-Mubarak in al-Zuhd (2/19), Abu Nu`aym in al-Hilyah (1/212), and Ibn `Asakir in Tarikh Dimashq (47/160).
❖ Abu Hurayrah said: “Those who will be sitting with Allah tomorrow are those of awe and asceticism.”  al-Risalah al-Qushayriyyah (1/236).
❖ Abu Sulayman al-Darani said: “Having awe is the first step to asceticism, just as contentment is the first step to being pleased with Allah.”  Madarij al-Salikin, Ibn al-Qayyim (2/24).
❖ Sufyan al-Thawri said: “I have never seen anything easier than having awe - whatever makes you uncomfortable, leave it off.”  The previous source. Categories of Awe  Majmu` al-Fatawa, Ibn Taymiyyah (20/137).
Legislated awe: it is avoiding what one fears may be a cause of blame and punishment without there being a clear preposition to this view. This entails performing actions that seem like obligations, and leaving off ones that seem like the impermissible. Obligatory awe: it is avoiding what is a cause of blame and punishment by performing the obligatory and leaving the impermissible. Corrupt awe: many people are put off by things due to habits and similar factors. This facilitates them being viewed as impermissible in their eyes. Some of them delve in false whims and doubts, establishing within them a corrupt awe. They are among those about whom Allah, exalted, says: “They follow but assumptions and the desires of their souls.” al-Najm: 23. The awe held by the innovators from this type is plentiful. Benefits of Awe and its Impact
Brings about Allah’s love, sanctified and exalted. Through it, one leaves off doubtful matters. Through it, one’s food and drink is good. It is a reason for one’s supplication to be answered. It preserves one’s innocence and honour. It is a reason for complete piety. Levels of Awe
Having awe is three levels: Avoiding ugly things to protect the self, and preserve one’s good deeds and faith. Making the limits at what is in fact unproblematic, ensuring preservation and piety, arising above lowliness, and being far from trespassing true boundaries. Having awe away from every call towards time wasting, or that which calls to habituating the self to a lack of focus, or any temporal event distracting at the time of efficacy.  Madarij al-Salikin, Ibn al-Qayyim (2/22). Forms and Manifestations of Awe
Having awe with one’s sight: The Prophet ﷺ told `Ali, Allah be pleased with him: “Do not follow up a look with another. For you is the first, but not the second.”  Reported by Abu Dawud (2149), al-Tirmidhi (2777), and Ahmad (22974). al-Hakim authenticated it according to the conditions of Muslim in al-Mustadrak (2/212) and al-Dhahabi agreed with him. al-Albani classified it as sound in Sahih Sunan al-Tirmidhi (2777). Having awe in hearing. Having awe with one’s tongue: `Umar ibn al-Khattab saw Abu Bakr, Allah have mercy upon them both, extending his tongue. He asked: “What are you doing, Successor of Allah’s Messenger?” He replied: “This thing put me in the worst of situations. Allah’s Messenger ﷺ said: ‘There is not a part of the body but it complains to Allah of the tongue from its sharpness.’”  Reported by Ibn Abi al-Dunya in al-Samt (13), Abu Ya`la (5), and al-Bayhaqi in Shu`ab al-Iman (4947). Having awe with one’s stomach: Allah's Messenger ﷺ said: “Allah is Good and He accepts only that which is good. Allah commanded the believers as He commanded the Messengers by saying: ‘Messengers, eat of the good things, and do good deeds.’ al-Mu’minun: 51; and He said: ‘Believers, eat of the good things that We gave you.’ al-Baqarah: 172. He then made mention of a person who travels widely, his hair disheveled and covered with dust. He lifts his hand towards the sky supplicating: "My Lord, my Lord," whereas his diet is unlawful, his drink is unlawful, his clothes are unlawful, and his nourishment is unlawful. How then can his supplication be accepted?”  Reported by Muslim (1015). Having awe of giving religious verdict: al-Bara’, Allah be pleased with him, said: “I saw three-hundred from those who witnessed Badr, and did not see one of them but that he preferred that another gives a religious verdict in his place.”  Reported by al-Khatib in Tarikh Baghdad (8/276). Means to Acquiring Awe
It is through five things: Knowledge. Using that knowledge to remember what is upon him, and his desire for his reward. Recalling Allah’s greatness and His majesty, and His power and kingship. Recalling his shyness from the Overpowering King. Recalling his fear of Allah’s wrath, and it being brought about if he remains upon doubtful matters.  al-`Aql wa al-Hawa, al-Hakim al-Tirmidhi (p. 6-7). Examples of Awe from the Life of the Prophet ﷺ, Companions, and Predecessors
❖ The Prophet ﷺ passed by a fallen date. He said: ‘If not that it may be charity, I would have eaten it.”  Reported by al-Bukhari (2055) and this is his wording, as well as Muslim (1071).
❖ Abu Hurayrah, Allah be pleased with him, narrates that al-Hasan, the son of `Ali, took a date from a bunch intended from charity and put it in his mouth. Thereupon the Messenger of Allah ﷺ said to him in Persian: “Kikh, kikh! Throw it away. Have you not learnt that we do not take charity?”  Reported by al-Bukhari (3072) and this is his wording, as well as Muslim (1069).
❖ `Umar, Allah be pleased with him, said: “I do not see it as lawful that I eat from this wealth of yours other than I would eat with my own wealth: bread and oil, and bread and ghee.” He would then be brought a plate of oil, and another with ghee, but would excuse himself, saying: “I am an Arab man, and do not find oil decent.”  Reported by Ibn Abi al-Dunya in al-Wara` (190).
❖ Ibn al-Sammak said: “`Umar ibn `Abd al-`Aziz was sharing apples for the people, then one of his sons came and took an apple from those he was sharing. `Umar got up after him, opened his fist, and took the apple and placed it back. The boy ran to his mother crying. She said to him: ‘What is it, dear boy?’ He told her what happened. She sent for apples with two dirhams, ate, fed her son, and kept some for `Umar. When he was done he entered upon her, and she gave him the plate of apples. He asked: ‘Where is this from, Fatimah?’ She told him. He said: ‘Allah have mercy on you, I fancied it.’”  Reported by Ibn Abi al-Dunya in al-Wara` (223). Awe in Poetry
❖ The poet said:
“People’s religion is not destroyed but by greed,
Truly; and it is not rectified but by having awe.”  Mawarid al-Zam’an li-Durus al-Zaman, `Abd al-`Aziz al-Salman (3/43).
❖ Another said:
“Have awe, leave what irks you - all of it
completely - to what doesn’t, you will be safe.
Preserve your seven organs holistically, and
Take care of Allah’s rights with every Muslim.”  Tabaqat Sulaha’ al-Yaman, `Abd al-Wahhab al-Suksuki (1/301).