Riyad as-Salihin 386
Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "Allah, the Exalted, has said: 'I will declare war against him who treats with hostility a pious worshipper of Mine. And the most beloved thing with which My slave comes nearer to Me, is what I have enjoined upon him; and My slave keeps on coming closer to Me through performing Nawafil (voluntary prayers or doing extra deeds besides what is obligatory) until I love him, (so much so that) I become his hearing with which he hears, and his sight with which he sees, and his hand with which he strikes, and his leg with which he walks; and if he asks Me something, I will surely give him, and if he seeks My Protection (refuge), I will surely protect him". [Al-Bukhari]
وعن أبي هريرة رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏"‏إن الله تعالى قال‏:‏ ‏"‏من عاد لي وليَّا، فقد آذنته بالحرب، وما تقرب إلي عبدي بشيء أحب إليَّ مما افترضت عليه، وما يزال عبدي يتقرب إليَّ بالنوافل حتى أحبه فإذا أحببته كنت سمعه الذي يسمع به، وبصره الذي يبصر به، ويده التي يبطش بها، ورجله التي يمشي بها، وإن سألني، أعطيته، ولئن استعاذني، لأعيذنه‏"‏ ‏(‏‏(‏رواه البخاري‏)‏‏)‏‏.‏