Naming Ali (ع) as Amir-ul-Mu’minin

Huzaifa narrates that the Messenger of Allah (ص) said:

﴿ لَوْ عَلِمَ النَّاسُ مَتَی سُمِّيَ عَلِيٌّ أَمِير الْـمُؤْمِنينَ مَا أَنْكَرُوا فَضْلَهُ، سُمِّيَ أَمِير الْـمُؤْمِنِينَ وَآدَمُ بَيْنَ الرُّوحِ وَالْـجَسَدِ. قَالَ اللهُ عَزَّ وَجَلَّ: ﴿وَإذْ أَخَذَ رَبُّكَ مِنْ بَنِي آدَمَ مِنْ ظُهُورِهِمْ ذُرِيَّتَهُمْ وَ أشْهَدَهُمْ عَلَی أَنْفُسِهِمْ أَلَسْتُ بِرَبِّكُمْ﴾ قَالَتِ الْـمَلَائِكَةُ: بَلَی. فَقَالَ تَبَارَكَ وَتَعَالیَ:‌ «أَنَا رَبُّكُمْ وَمُحَمَّدٌ نَبِيُّكُمْ وَعَلِيٌ أَمِيرُكُمْ ﴾

"If the people knew since when Ali was named “Amir-ul-Mu’minin (the Commander of the Faithful), they would not have denied his grace and superiority. He further said, “He was called Amir-ul-Mu’minin while Adam was in his body at the time of breathing of spirit” [1]