If you want to cry, then weep over the world’s biggest victim.

Imam al-Sadiq (a) said about Karbala:
إنّ يوم عاشورا أحرق قلوبنا، وأرسل دموعنا، وأرض كربلاء أورثتنا الكرب والبلاء، فعلي مثل الحسين فليبك الباكون، فإنّ البكاء عليه يمحو الذنوب أيّها المؤمنون.
The event of Karbala sets our hearts on fire and releases our tears. We are the inheritors of the sorrow of karbala. Therefore, those who weep should weep over people like Husayn (a), because mourning on them eliminates sins.
نور العين في مشهد الحسين، أبو إسحاق اسفراييني، ص 84.
عنِ الرَّيَّانِ بْنِ شَبِيبٍ قَالَ: دَخَلْتُ عَلَى الرِّضَا ع فِي أَوَّلِ يَوْمٍ مِنَ الْمُحَرَّمِ- فَقَالَ لِي يَا ابْنَ شَبِيبٍ أَ صَائِمٌ أَنْتَ فَقُلْتُ لَا فَقَالَ إِنَّ هَذَا الْيَوْمَ هُوَ الْيَوْمُ الَّذِي دَعَا فِيهِ زَكَرِيَّا ع رَبَّهُ عَزَّ وَ جَلَّ فَقَالَ‌ رَبِّ هَبْ لِي مِنْ لَدُنْكَ ذُرِّيَّةً طَيِّبَةً إِنَّكَ سَمِيعُ الدُّعاءِ فَاسْتَجَابَ اللَّهُ لَهُ وَ أَمَرَ الْمَلَائِكَةَ فَنَادَتْ زَكَرِيَّا وَ هُوَ قائِمٌ يُصَلِّي فِي الْمِحْرابِ أَنَّ اللَّهَ يُبَشِّرُكَ بِيَحْيى‌ فَمَنْ صَامَ هَذَا الْيَوْمَ ثُمَّ دَعَا اللَّهَ عَزَّ وَ جَلَّ اسْتَجَابَ اللَّهُ لَهُ كَمَااسْتَجَابَ لِزَكَرِيَّا ع ثُمَّ قَالَ يَا ابْنَ شَبِيبٍ إِنَّ الْمُحَرَّمَ هُوَ الشَّهْرُ الَّذِي كَانَ أَهْلُ الْجَاهِلِيَّةِ فِيمَا مَضَى يُحَرِّمُونَ فِيهِ الظُّلْمَ وَ الْقِتَالَ لِحُرْمَتِهِ فَمَا عَرَفَتْ هَذِهِ الْأُمَّةُ حُرْمَةَ شَهْرِهَا وَ لَا حُرْمَةَ نَبِيِّهَا ص لَقَدْ قَتَلُوا فِي هَذَا الشَّهْرِ ذُرِّيَّتَهُ وَ سَبَوْا نِسَاءَهُ وَ انْتَهَبُوا ثَقَلَهُ فَلَا غَفَرَ اللَّهُ لَهُمْ ذَلِكَ أَبَداً يَا ابْنَ شَبِيبٍ إِنْ كُنْتَ بَاكِياً لِشَيْ‌ءٍ فَابْكِ لِلْحُسَيْنِ بْنِ عَلِيِّ بْنِ أَبِي طَالِبٍ ع فَإِنَّهُ‌ ذُبِحَ‌ كَمَا يُذْبَحُ‌ الْكَبْشُ‌ وَ قُتِلَ مَعَهُ مِنْ أَهْلِ بَيْتِهِ ثَمَانِيَةَ عَشَرَ رَجُلًا مَا لَهُمْ فِي الْأَرْضِ شَبِيهُونَ وَ لَقَدْ بَكَتِ السَّمَاوَاتُ السَّبْعُ وَ الْأَرَضُونَ لِقَتْلِهِ وَ لَقَدْ نَزَلَ إِلَى الْأَرْضِ مِنَ الْمَلَائِكَةِ أَرْبَعَةُ آلَافٍ لِنَصْرِهِ فَوَجَدُوهُ قَدْ قُتِلَ فَهُمْ عِنْدَ قَبْرِهِ شُعْثٌ غُبْرٌ إِلَى أَنْ يَقُومَ الْقَائِمُ فَيَكُونُونَ مِنْ أَنْصَارِهِ وَ شِعَارُهُمْ يَا لَثَارَاتِ الْحُسَيْنِ يَا ابْنَ شَبِيبٍ لَقَدْ حَدَّثَنِي أَبِي عَنْ أَبِيهِ عَنْ جَدِّهِ ع أَنَّهُ لَمَّا قُتِلَ الْحُسَيْنُ جَدِّي ص مَطَرَتِ السَّمَاءُ دَماً وَ تُرَاباً أَحْمَرَ يَا ابْنَ شَبِيبٍ إِنْ بَكَيْتَ عَلَى الْحُسَيْنِ ع حَتَّى تَصِيرَ دُمُوعُكَ عَلَى خَدَّيْكَ غَفَرَ اللَّهُ لَكَ كُلَّ ذَنْبٍ أَذْنَبْتَهُ صَغِيراً كَانَ أَوْ كَبِيراً قَلِيلًا كَانَ أَوْ كَثِيراً يَا ابْنَ شَبِيبٍ إِنْ سَرَّكَ أَنْ تَلْقَى اللَّهَ عَزَّ وَ جَلَّ وَ لَا ذَنْبَ عَلَيْكَ فَزُرِ الْحُسَيْنَ ع يَا ابْنَ شَبِيبٍ إِنْ سَرَّكَ أَنْ تَسْكُنَ الْغُرَفَ الْمَبْنِيَّةَ فِي الْجَنَّةِ مَعَ النَّبِيِّ وَ آلِهِ ص فَالْعَنْ قَتَلَةَ الْحُسَيْنِ يَا ابْنَ شَبِيبٍ إِنْ سَرَّكَ أَنْ تَكُونَ لَكَ مِنَ الثَّوَابِ مِثْلَ مَا لِمَنِ اسْتُشْهِدَ مَعَ الْحُسَيْنِ ع فَقُلْ مَتَى مَا ذَكَرْتَهُ‌ يا لَيْتَنِي كُنْتُ مَعَهُمْ فَأَفُوزَ فَوْزاً عَظِيماً يَا ابْنَ شَبِيبٍ إِنْ سَرَّكَ أَنْ تَكُونَ مَعَنَا فِي الدَّرَجَاتِ الْعُلَى مِنَ الْجِنَانِ فَاحْزَنْ لِحُزْنِنَا وَ افْرَحْ لِفَرَحِنَا وَ عَلَيْكَ بِوَلَايَتِنَا فَلَوْ أَنَّ رَجُلًا تَوَلَّى حَجَراً لَحَشَرَهُ اللَّهُ مَعَهُ يَوْمَ الْقِيَامَةِ.
Rayan bin Shabeeb said: I came to imam al-Rida (a) on the first Muharram. He said to me:
۔ O Ibn Shabeeb, are you fasting? I said: No. He said: “Today is the day on which Hazrat Zakariya (a) prayed to his Lord and said, “Give me a pure generation, for You are the Hearer of supplications.” When God accepted the prayer and commanded the angels, Malaika said to Zakaria while they were engaged in worship: “God gives you the good news of Yahya.” Whoever fasts on this day and then prays to God, God accepts his prayer, just as he accepted the prayer of Hazrat Zakariya.
۔ He then said: “O Ibn Shabeeb! Of course, Muharram is the month that even the people of jahiliyya considered killing to be haraam in honor of this month, but this ummah did not respect this month nor did they take care of the sanctity of their Prophet (s). They killed the children of the Prophet (s) in this month, took their women captive and looted their wealth. God will never forgive their sin.
O Ibn Shabeeb: If you want to pray for something, pray for Husayn ibn ‘Ali ibn Abi Talib (a) because he was slaughtered like a sheep, and eighteen of his ahl al-bayt were martyred, who had no precedent on earth. On his murder, the seven earth and the heavens mourned. 4,000 angels descended on the earth to support Imam (a). Since then, these angels have been disturbed and dusted at his grave and will be in the same condition until the appearance of Qaim al-Muhammad (a).
۔ O Ibn Shabeeb! My father has heard from his father and he has heard from his grandfather: Blood and red soil rained from the sky on the murder of my grandfather Imam Al-Husayn (a).
۔ O Ibn Shabeeb! If you are so angry with Husayn (a) until your tears reach your cheeks, Allah will forgive you all your sins, whether they are small or big, less or more.
۔ O Ibn Shabeeb! If you want to meet God in such a way that you do not have any sin, then visit Husayn (a).
O Ibn Shabeeb! If you want to stay in Paradise with the Prophet (s), then curse the killers of Husayn (a).
۔ O Ibn Shabeeb! If you want to get the reward of the companions who were martyred with Imam al-Husayn (a), whenever you remember Al-Husayn (a), say, “Ya litni kant muham fafuz fuza azeema” (I wish I had been with him and attained great martyrdom). )
۔ O Ibn Shabeeb! If you want to live with us in the highest degrees of paradise, then rejoice in our sorrow and rejoice in our happiness. And our will is obligatory upon you, because if a person loves a stone, Allah will make him with that stone on the Day of Resurrection.
Sa’il al-Shi’a, vol. 14, p. 502, Bab Istahab al-Baqa’a l-Qatal al-Husayn, al-‘Amali (l-Saduq), p. 130, al-Majlis al-Sa’ba wa al-Ashron.
Amaranjafi