Musnad Abu Ya'la al-Mawsili 154:83

Abu Musa Muhammad ibn al-Muthanna narrated to us, Bakr ibn Bakkar narrated to us, Yusuf ibn Suhayb narrated to us, from Zayd al-Ammi, from Ibn Umar, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever among you loves for his supplication to be answered and his distress to be relieved, let him make things easy for one in hardship."