That when the Messenger of God (PBUH) sent Ali on one of his missions, he said: O Messenger of God, do you send me on an affair to be in it like a heated iron brand in the eye, or is it that the one present sees what the absent one does not see? He said: Rather, the one present sees what the absent one does not see. (Ayn al-Ibra, vol. 1, p. 5)
The Messenger of God (PBUH) used repeatedly to send Ali (AS) on missions. One day Ali (AS) asked: When you entrust a mission to me, am I to carry out exactly what you have said, or am I to decide according to the circumstances and conditions? The Messenger of God (PBUH) said: Act according to what you yourself judge best, for you are there and can weigh the circumstances, whereas I am not there!
Were the veil lifted for me, I would not increase in certainty. (Ayn al-Ibra, vol. 1, p. 22)
Ali (AS) said: If the veil were drawn aside and the unseen were disclosed to me, nothing would be added to my certainty.