Riyad as-Salihin

Anas (May Allah be pleased with him) reported: The Prophet (ﷺ) said, "Allah says: ' When a slave of Mine draws near to Me a span, I draw near to him a cubit; and if he draws near to Me a cubit, I draw near to him a fathom. And if he comes to Me walking, I go to him running."'.

[Al-Bukhari].