"It is narrated by Mu‘ādh bin Jabal that he heard the Messenger of Allāh (صلى الله عليه وآله وسلم) saying:

   Allāh the Exalted and Almighty said: ‘My love has been made obligatory for those two persons who love each other on My count and spend time together for My sake, and see each other for My sake and give money to each other generously for My sake.’"

This sahīh (sound) hadīth narrated by Mālik bin Anas in al-Muwattā, b. of sha‘ar (hair) ch.5 (2:954#16), and Ibn ‘Abd-ul-Barr said its chain is good. Ahmad bin Hambal also transmitted it in his Musnad (5:233); Hākim in al-Mustadrak (4:169), who graded it sahīh, and also confirmed by Dhahabī; Baghawī in Sharh-us-sunnah, (13:49-50#3463); Khatīb Tabrīzī in Mishkāt-ul-masābīh, b. of ādāb (good manners) ch.16 (3:75#5011). [src: Ch3 of Beseeching for Help, Tahir-ul-Qadri]

Allah Most High says: "He who is hostile to a friend of Mine I declare war against. My slave approaches Me with nothing more beloved to Me than what I have made obligatory upon him, and My slave keeps drawing nearer to Me with voluntary works until I love him. And when I love him, I am his hearing with which he hears, his sight with which he sees, his hand with which he seizes, and his foot with which he walks. If he asks me, I will surely give to him, and if he seeks refuge in Me, I will surely protect him"

(Sahih Bukhari - Fath al-Bari, 11.340 41, hadith 6502) [src: suhba.org]