"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]

A man said to the Prophet (peace be upon him): By Allah, O Messenger of Allah, I do love you. The Prophet (peace be upon him) said: Look, what you are saying? The man said: By Allah, I love you, and repeated this sentence thrice. The Prophet (peace be upon him) said: If you really love me, then be prepared for acute poverty, for extreme hardship rushes more rapidly towards a person who loves me, than a flood flows towards its goal. "

(Narrated Abdullah ibn Mughaffal - al-Tirmidhi) [src: alim.org]