Qasim narrates that I was sitting with Sayyiduna Ibn Abbas (may Allah be pleased with them) when a man asked him about the ruling of killing a locust while in the state of Ihram. Ibn Abbas (may Allah be pleased with them) replied: "For this, a handful of food (as compensation) is required, and he should definitely catch a handful of locusts." Imam Shafi’i (may Allah have mercy on him) says that Sayyiduna Ibn Abbas’s statement that he should catch a handful of locusts means that only the value will be considered, and his saying «ولو» means that caution will be exercised in paying that value, and he will give more than what is obligatory upon him, after I have informed you that it is more than what is obligatory upon you.
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 897
Hadith Takhrijإسنادہ حسن أخرجہ البیہقی: 5 / 206 - وفی معرفۃ السنن والآثار لہ (3216)۔ وعبد الرزاق (8244)۔