"Aisha reported: The Messenger of Allah, peace and blessings be upon him, placed my chin on his shoulder so I could look at the Abyssinians until I felt tired and turned away from them. Urwa said: I heard Aisha say the Messenger of Allah said on that day, “So the Jews will know that there is flexibility in our religion. Verily, I have been sent with a lenient, upright religion.”"
Source: Musnad Ahmad 24333 - Grade: Sahih (authentic) according to Ahmad Shakir
"Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “A person might fast and he gets nothing from his fast but hunger. A person might pray at night but he gets nothing from his prayer but sleeplessness.”"
Source: Sunan Ibn Majah 1690 - Grade: Sahih (authentic) according to As-Suyuti