Musnad Abu Ya'la al-Mawsili 150:446

Suwayd ibn Sa'id narrated to us, Ali ibn Mushir narrated to us, from Yusuf ibn Maymun, from 'Ata, from 'Aisha, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever is pleased to outstrip the diligent striver, let him refrain from sins."