Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Bara bin Azib (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: “By «السري» is meant a river.”

It is narrated from Sayyiduna Ali (may Allah be pleased with him), he says: I said: O Messenger of Allah! Since you are sending me, should I become like a heated coin (i.e., act strictly on your command) or like one who is present and sees what the absent cannot see? The Prophet (peace and blessings of Allah be upon him) said: "Like one who is present and sees what the absent cannot see."