In a report of Abu Hashim: One day, Imam Ali al-Naqi(a.s) began to speak Hindi and I said: Maula, I don’t understand this language at all. He picked up a pebble and applied saliva to it; when I placed it on my tongue I became proficient in seventy languages.
It is obvious that when such is the effect of the saliva of Imamate what would be the effect of saliva of prophethood and when such effect is found in saliva, which is considered to be an extra moisture of the body, what would be the effect of blood, which is the real part of the body and an element of life.
Only after realizing this matter can the following statement of the Prophet be explained: The blood of Ahle Bayt (a.s) is my blood and their flesh and skin is my flesh and skin.
It is important to notice that Abu Hashim after placing the pebble on his tongue did not only know how to speak seventy languages, but he attained mastery and became expert(proficient) in those languages.
Elaamul Wara, Pg. 243;
Biharul Anwar, Vol. 9, Chap. 3, Pg. 126;
Mukhtarul Kharaij wal Jaraih, Pg. 237