It is narrated from Yusuf bin Mahak that Abdullah bin Abi Ammar told him that he came with Mu'adh bin Jabal and Ka'b al-Ahbar (may Allah be pleased with them both) among the people in the state of ihram for 'Umrah from Bayt al-Maqdis. When we were on the way and Ka'b was warming himself by a fire, a swarm of locusts passed by him, so he caught two locusts and roasted them, forgetting that he was in ihram. Then, when he remembered that he was in ihram, he threw them away. When we came to Madinah, the people went to 'Umar (may Allah be pleased with him), and I also went. Ka'b (may Allah be pleased with him) related the incident of the locusts to 'Umar (may Allah be pleased with him). 'Umar (may Allah be pleased with him) asked: "Who is that? Perhaps, O Ka'b, it is you?" Ka'b said: "Yes." 'Umar (may Allah be pleased with him) said: "Indeed, Himyar (an ancient tribe of Yemen) likes locusts." 'Umar (may Allah be pleased with him) said: "How much fidyah (compensation) have you calculated for yourself?" He replied: "Two dirhams." 'Umar (may Allah be pleased with him) said: "Wow! Two dirhams are better than a hundred locusts, so keep what you have calculated for yourself."
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 894