Gleanings — Paragraph 576
Source (Arabic)
ومثلهم عند اللّه كمثل السّراج ليستضيء منه العباد وهو يحترق في نفسه ويكون
Translation
Should such a man ever succeed in influencing anyone, this success should be attributed not to him, but rather to the influence of the words of God, as decreed by Him Who is the Almighty, the All-Wise. In the sight of God he is regarded as a lamp that imparteth its light, and yet is all the while being consumed within itself.