From al-Mufaddal (from him is peace), our Master Assadiq (may his glory be exalted) said: "Indeed, our speech has an outer and an inner. Its outer is precise and elegant, and its inner is profound. Our Hadith is difficult, hard to bear, and our affair is a deeply hidden secret. So whoever knows us and knows our nuance knows what we intended. And whoever does not know the hinting will not benefit from the explicit statement."1
From Dawud ibn Farqad, I heard our Master Abu 'Abdillah Assadiq (may his glory be exalted) say: "You are the most understanding of people if you know the meanings of our speech. The word may be turned in [many] facets. If a person wished, he could turn his speech however he wished without lying."2
Our Master Assadiq (may his glory be exalted) said to al-Mufaddal (from him is peace): "Whoever knows the allusion becomes needless of the expression. And whoever knows the locations of the attribute reaches the foundation of Gnosis."3
So, whoever is not from the people of allusions, the expressions will not benefit him.
It is also useful for the reader to point out that one of the keys to knowing the type of Hadith and the nuance of their speech is knowing the status of the narrator from the Imam and the questioner. You must know if the questioner is one of the "Gates" or the people of ranks, or from the "detractors" (those who fall short), or from the "weakened." Based on his status will be the Imam's answer to him, whether it is an explicit statement, a hinting, an obfuscation, or a dissimulation. The answer will also be according to the measure of the question. If he had added a letter, the Imam would have added to the answer. So, knowing the question and the state in which he asked is likewise important.
The topic of allusion, O believer, exists in comparative religion. If a Christian sat now with a Jew, the Christian (whose religion came after Judaism) would begin to argue against the Jew for the prophethood of the Lord Christ from the Torah and show him some allusions from the Old Testament.