It is narrated from Sayyiduna Dhu al-Lihyah al-Kilabi (may Allah be pleased with him) that he said: O Messenger of Allah, are we acting in a matter that is newly begun, or in a matter that has already been settled? He (peace and blessings be upon him) said: "No, rather in a matter that has already been settled." He said: Then why act? He (peace and blessings be upon him) said: "Act, for each person is made easy for that for which he was created."
Hadith Referenceالمعجم الكبير للطبراني / باب الذال / 4221