It is narrated from a Sheikh of Banu Sulayt that once I heard the Prophet (peace be upon him) saying in his presence: "A Muslim is the brother of a Muslim; he does not oppress him nor does he abandon him helpless. Taqwa is here, Taqwa is here," and he pointed with his hand towards his chest.
Hadith Referenceمسند احمد / أول مسند البصريين / 20288
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد ضعيف لضعف على بن زيد، ولكنه توبع