The station of Messengership requires both truthfulness and Safe keeping. The safe keeping is required because the Apostle has to convey the message verbatim to the people and to keep the message safe.
Truthfulness and safekeeping actual are the same. Sidq is safekeeping hadith and safekeeping is truthfulness in deed. This is why the Qura’n in the 3rd verse has said: (The people of Noah denied him as an apostle) and he said, “I am your trust worthy Messenger.” The same features have been mentioned for the apostle Huod in 125 Shuara, Saleh 143 Shuara, lot 162 Shuara, Shoaeb 178 Shuara, Moses 18 Dukhan.
There is no doubt that all the messengers of God were steadfast in keeping the trust. We have read about the last messenger being called “Mohammad As-Sadiqol Ameen” and known to all. And this was before the first revelation. So how can people not confirm their truthful ness in both deeds and trust. (1)
It is notable that Qura’n has described one feature of Gabriel as He was the safe keeper of the revelations of God. It is said, “With it came down the truthful spirit to your heart so that you may admonish.” (As- Shuara 193-194)
Actually other than the angels the safe keeper of the revelations are those who are the intermediaries either the prophets or the infallible ones and who have the capacity to safe keep and be responsible for the revelations. They are the trust worthy people from God. The first among them was Hazrat ALI then the other Imams and he has been called “Aminullah” in the famous ziyarets. “Salaam to you O safe keeper of God’s trust in this world.” And this is the proof of this contention.