It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Allah Almighty says, "I deal with My servant according to his expectation of Me. Whenever he remembers Me, I am with him. If he remembers Me in his heart, I also remember him in My heart. If he remembers Me in a gathering, I remember him in a better gathering. If he comes near Me by a handspan, I come near him by an arm's length. If he comes near Me by an arm's length, I come near him by a fathom. And if he comes to Me walking, I come to him running."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10224