Some of the narrations on al-Khushoo`:

بسم الله والحمد لله والصلاة والسلام على رسول الله ، وبعد

Some of the Companions رضي الله عنهم, namely, Hudhaifah used to say: “Beware of Khushoo` al-Nifaaq (hypocritical humility). It was said to him: And what is hypocritical humility? He said: When you notice the body to be humble and whereas the heart is not.”

`Umar Ibn al-Khattaab رضي الله عنه saw a man bowing his neck in the prayer, so he said to him: “O companion of the (bend) neck! Raise your neck. Khushoo` is not in (bending) the neck, rather al-Khushoo` is in the heart.”

`Aaishah رضي الله عنها saw some youths passing by and they were swaying in their walk. She asked her companions: Who are they? They replied: These are the ascetics. She رضي الله عنها said: “`Umar Ibn al-Khattaab رضي الله عنه, when he walked, he was quick; when he spoke, he was heard; if he hit (someone), it would hurt; if he ate, he would eat till satisfaction; and indeed he was a true devout person.”

Al-Fudhail bin `Iyaadh said: “They (the Salaf) used to detest that a man is seen with devotion that is more than what is in his heart.”

[Madaarij al-Saalikeen (1/517)]