Musnad Ahmad 1153:605

Harun ibn Ma'ruf narrated to us, he said: Ibn Wahb informed us, he said: Harmalah narrated to us, from Abd al-Rahman ibn Shamasa, he said: I came to Aisha, the wife of the Prophet, may Allah bless him and grant him peace, to ask her about something. She said: I will inform you of what I heard the Messenger of Allah, may Allah bless him and grant him peace, saying in this house of mine: "O Allah, whoever is entrusted with any of the affairs of my Ummah and makes it difficult for them, then make it difficult for him; and whoever is entrusted with any of the affairs of my Ummah and is gentle with them, then be gentle with him."