Alright...The book is called "Wasa2el l Shi3a"....
And this is the quote....
3an el sadek wa 3an el 3omrky ben ali....3an 3ali bn ja3far...3an akhih abi el 7asann kal sa2altoho 3an moslem tanassar,kal : yoktal wala yostatab....kolto fa nasrani aslam thomma rtad..kal : yostatab fa 2en raje3...wa illa kotil
I will try to find the book here and buy it...i can then include the page...I am sure there is another quote referenced to one of the 12 imams (most probably Ali)...I just can't remember where i read it and its degree of strength....
Peace 