Once when Allah's Messenger (peace be upon him) was with a number of the Emigrants and Helpers a camel came and prostrated itself before him. Thereupon his companions said, "Messenger of Allah (peace be upon him) beasts and trees prostrate themselves before you, but we have the greatest right to do so." He replied, "Worship your Lord and honour your brother. If I were to order anyone to prostrate himself before another, I should order a woman to prostrate herself before her husband. If he were to order her to convey stones from a yellow mountain to a black one, or from a black mountain to a white one, it would be incumbent on her to do so."
Ahmad transmitted it.