(37) بَابُ قَوْلِ اللَّهِ تَعَالَى: {مَنْ يَشْفَعْ شَفَاعَةً حَسَنَةً يَكُنْ لَهُ نَصِيبٌ مِنْهَا وَمَنْ يَشْفَعْ شَفَاعَةً سَيِّئَةً يَكُنْ لَهُ كِفْلٌ مِنْهَا وَكَانَ اللَّهُ عَلَى كُلِّ شَيْءٍ مُقِيتًا}
Narrated Abu Musa:
Whenever a beggar or a person in need came to the Prophet, the Prophetwould say "Help and recommend him and you will receive the reward for it, and Allah will bring about what he will through His Prophet's tongue
Reference: Sahih al-Bukhari 6028
In-book reference: Book 78, Hadith 58
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 73, Hadith 56