Jesus went into the wilderness beyond Jordan with his disciples, and when the midday prayer was done he sat down near to a palm-tree, and under the shadow of the palm-tree his disciples sat down. Then Jesus said: 'So secret is predestination, O brethren, that I say to you, truly, only to one man shall it be clearly known. He it is whom the nations look for, to whom the secrets of God are so clear that, when he comes into the world, blessed shall they be that shall listen to his words, because God shall overshadow them with his mercy even as this palm-tree overshadows us. Yes, even as this tree protects us from the burning heat of the sun, even so the mercy of God will protect from Satan them that believe in that man.'

The disciples answered, "O Master, who shall that man be of whom you speak, who shall come into the world?" Jesus answered with joy of heart: 'He is Muhammad;, Messenger of God, and when he comes into the world, even as the rain makes the earth to bear fruit when for a long time it has not rained, even so shall he be occasion of good works among men, through the abundant mercy which he shall bring. For he is a white cloud full of the mercy of God, which mercy God shall sprinkle upon the faithful like rain.'

Reference: The Gospel of Barnabas, Chapter 163