What is the ruling on applying perfume before entering into a state of Ihram?

Perfuming oneself after ghusl and before ihram is a Sunnah. Aisha, may Allah be pleased with her, used to perfume the Prophet, peace and blessings be upon him, for his ihram before he entered into it, and the glistening of musk could be seen in the partings of his hair while he was in ihram.