It is narrated from Hazrat Utbah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) forbade plucking the hair of horses’ tails, manes, and forelocks, and said: Their tails are a fly-whisk for them, their manes are a means of protection from the cold, and goodness has been placed in their forelocks until the Day of Resurrection.
Hadith Referenceمسند احمد / مسند الشاميين / 17638
Hadith Gradingحکم دارالسلام:إسناده ضعيف لاضطرابه، فقد اختلف فيه على ثور بن يزيد، ثم إسناده منقطع، ثور لم يسمع من عتبة بن عبد