Narrated Jarir bin Abdullah
Prophet Muhammad sallallahu alaihi wa sallam said,"Allah will not be merciful to those who are not merciful to mankind."
Bukhari 9.473

"Usse bada gumrah kaun hain jo Allah ke alawa unhe pukare jo qayamat tak jawab nahi de sakte balki wo unki pukar hi se bekhabar hai"
Quran