عَنِ الْحُسَيْنِ بْنِ عَلِيٍّ عَنْ اَبِيْهِ صَلَوَاتُ اللهِ عَلَيْهِمْ قَالَ لَمَّا نَزَلَتْ الم اَ حَسِبَ النَّاسُ اَنْ يُتْرَكُوا اَنْ يَقُولُوا آمَنَّا وَ هُمْ لَا يُفْتَنُوْنَ قَالَ قُلْتُ يَا رَسُولَ اللهِ مَا هٰذِهِ الْفِتْنَةُ قَالَ يَا عَلِيُّ اِنَّكَ مُبْتَلًى بِكَ وَ اِنَّكَ مُخَاصَمٌ فَاَعِدَّ لِلْخُصُومَةِ
Imam Husain (peace be upon him) reports from his father (peace be upon him), “When the verse ‘Alif Laam Meem. Do the people think they will be left when they say we have believed and they will not be tested?’ was revealed, I asked, ‘O Messenger of Allah! What is this test?’ He (peace be upon him and his holy progeny) replied, ‘O Ali! You are the one through whom the people will be tested and you are the one who will be argued with. So be prepared for the argument’.”
Note:
The people will be tested through Ameerul Momineen (peace be upon him) and other Imams (peace be upon them) vis-à-vis their beliefs in them (peace be upon him), their sayings, their acts, etc. and also as per the levels of the people.
All the scholars will also be tested through the people; again, depending upon their levels.
References:
1. Behaar al-Anwaar, vol. 24, p. 228, H. 26
2. Taveel al-Ayaat al-Zaaherah under the aforementioned verse