Al-Adab Al-Mufrad 85
Ibn Abi Nu'm said, "I was with Ibn 'Umar when a man asked him about the blood of gnats. He asked, 'Where are you from?' 'From the people of Iraq,' he replied. He said, 'Look at this man! He asks about the blood of gnats when they murdered the grandson of the Prophet, may Allah bless him and grant him peace! I heard the Prophet ﷺ say, 'They are my sweet basil in this world.'"
حَدَّثَنَا مُوسَى، قَالَ: حَدَّثَنَا مَهْدِيُّ بْنُ مَيْمُونٍ، قَالَ: حَدَّثَنَا ابْنُ أَبِي يَعْقُوبَ، عَنِ ابْنِ أَبِي نُعْمٍ قَالَ: كُنْتُ شَاهِدًا ابْنَ عُمَرَ إِذْ سَأَلَهُ رَجُلٌ عَنْ دَمِ الْبَعُوضَةِ؟ فَقَالَ: مِمَّنْ أَنْتَ؟ فَقَالَ: مِنْ أَهْلِ الْعِرَاقِ، فَقَالَ: انْظُرُوا إِلَى هَذَا، يَسْأَلُنِي عَنْ دَمِ الْبَعُوضَةِ، وَقَدْ قَتَلُوا ابْنَ النَّبِيِّ ﷺ، سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ: هُمَا رَيْحَانَيَّ مِنَ الدُّنْيَا.