It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: When any one of you applies kohl, he should apply it to his eyes in an odd number of strokes, and when he performs istinja with stones, he should also use an odd number of stones.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8611
Hadith Gradingحکم دارالسلام:حدیث حسن ، وھذا إسناد ضعیف لضعف ابن لھیعة