It is narrated from Hazrat Aisha (may Allah be pleased with her) that once the Prophet (peace and blessings be upon him) was in the mosque when he said to a slave girl, "Hand me the mat." The Prophet (peace and blessings be upon him) wanted to spread it out and pray on it. She informed him that she was in her menstrual period. The Prophet (peace and blessings be upon him) said, "Her 'period' has not affected her hand."
Hadith Referenceمسند احمد / مسند النساء / 25460
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد حسن، م: 298