It is narrated from Hazrat Suraqah (may Allah be pleased with him) that I was present in the service of the Prophet (peace and blessings be upon him) during his illness of death. I started asking the Prophet (peace and blessings be upon him) questions, until I ran out of questions. Then the Prophet (peace and blessings be upon him) said, "Remember some more." Among those questions, I also asked: "O Messenger of Allah! If stray camels come to my pond, will I get reward for giving them water, even though I have filled that water for my own camels?" The Prophet (peace and blessings be upon him) said, "Yes! There is reward in every living being with a moist liver."
Hadith Referenceمسند احمد / مسند الشاميين / 17587
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد مرسل، عبدالرحمن بن مالك لم يشهد القصة ، فهو تابعي