It is narrated from Hazrat Maymunah that once I was in a state of impurity, and ghusl was also obligatory on the Prophet (peace be upon him). I performed ghusl with water from a tub in which some water was left. When the Prophet (peace be upon him) came to perform ghusl, I said, "I have performed ghusl of janabah with this water." The Prophet (peace be upon him) said, "Janabah does not affect the water," and he performed ghusl with the same water.
Hadith Referenceمسند احمد / مسند النساء / 26802
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد ضعيف لضعف شريك، ورواية سماك عن عكرمة مضطربة