كتاب المقدمات
1
The Book of Miscellany
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 shows hostility to 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 (prayer or doing extra deeds besides what is obligatory) till I love him. When I love him I become his hearing with which he hears, his seeing with which he sees, his hand with which he strikes, and his leg with which he walks; and if he asks (something) from Me, I give him, and if he asks My Protection (refuge), I protect him".

[Al- Bukhari].

فالأول‏:‏ عن أبي هريرة رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏ "‏إن الله تعالى قال‏:‏ من عادى لي وليا فقد آذنته بالحرب‏.‏ وما تقرب إلي عبدي بشيء أحب إلي مما افترضت عليه، وما يزال عبدي يتقرب إلي 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)‏‏)‏‏.‏
Arabic/English book reference : Book 1, Hadith 95