The Holy Messenger of Allah the Almighty صلي الله عليه و سلم is quoted on the authority of Abu Huraira رضی الله تعلٰی عنه to have said:
“Allah the Almighty says, ‘I am towards My servant as he is towards Me. I am with him when he remembers Me (dhikr). If he remembers Me within himself, I remember him within Myself. If he remembers Me in a gathering, I remember him in a gathering better than it.’”
(Sahih Al-Bhukhari V2, P1101) [src] p5, 4 Natijatu Al-Fikr Fi Al-Jahri Fi Al-Dhikr (Outcome of Contemplation over Vociferous Dhikr) an extract from Al-Hawi Lil Fatawa by Jalal Al-Din Al-Suyuti رحمتاالله علیه, Dar-ul-Ehsan Publications