Both of them mean utter debasement in front of Allaah the Mighty and Majestic and total submission to Him, openly and in secret. This comes along with perfect love for Allaah the Blessed and Exalted. Due to this, the Scholars divided between al-khashyah (dread) and al-khawf (fear). They said, “Indeed, al-khashyah is fear accompanied by glorification, whereas al-khawf can be accompanied by glorification and it can occur without glorification as well.” And this is true, since a person can fear an enemy. However, his fear of the enemy does not mean that he glorifies him. And he could fear a predatory animal, but his fear of that animal does not mean that he glorifies it. However, al-khashyah cannot be applied unless it is accompanied by glorification.
Allaah the Mighty and Majestic said,
“And they stand in awe for fear of Him.” [Sooratul-Anbiyaa‘ 21:28]
Likewise, Allaah the Mighty and Majestic said about the Scholars who are the best of the creation,
“Indeed, those who fear Allaah the most from amongst His creation are the Scholars.” [Soorah Faatir 35:28]
That is, the Scholars of the Sharee’ah, the Scholars of the Book of Allaah and the Sunnah of His Prophet (’alayhis-salaatu was-salaam) who act upon their knowledge. So whoever observes this khashyah for other than Allaah, then he has committed Shirk. Allaah the Blessed and Exalted warned against that in His statement,
“So do not fear them, but fear Me.” [Sooratul-Baqarah 2:150]
Khasyah (awe) is fear founded upon knowledge of the greatness of the one whom you fear.It is something more particular than khawf. For example, if you fear someone but don’t know whether he is able to catch you or not, then this is khawf. But when you fear someone and know that he is fully able to seize hold of you then this is khashyah.
Taken from the below:
1. The Path To Attaining Clarification Concerning The Three Fundamental Principles – By The Noble Shaykh Zayd Ibn Muhammad Ibn Haadee Al-Madkhalee , Prepared By Fawaaz Ibn ’Alee Al-Madkhalee
2. A Gift For The Intellect In Explanation Of The Three Fundamental Principles Of Islaam : By Sheikh Ubaid Al-Jaabiree (Hafizahullah)