I became so infested with lice that I thought every hair on my head, from root to tip, was crawling with them. When the Prophet ﷺ saw this, he ordered me, "Shave your head." Then the verse was revealed, and he said, "Feed six poor people with three saa of dates."
حدثنا هشيم أخبرنا خالد عن أبي قلابة
قملت حتى ظننت أن كل شعرة من رأسي فيها القمل من أصلها إلى فرعها فأمرني النبي ﷺ حين رأى ذلك قال احلق ونزلت الآية قال أطعم ستة مساكين ثلاثة آصع من تمر
Its isnad is sahih, its narrators are trustworthy and well known. Khalid is Ibn Mihran al-Hazza, and Abu Qilaba is Abdullah bin Zayd al-Jarmi. The hadith is a continuation of the one before it.