It is narrated from Ibn Abbas (may Allah be pleased with him) that he was asked about ambergris, so he said: If there is anything in it, then it is the fifth part.
Hadith Referenceمسند الإمام الشافعي / كتاب الزكاة / 733
Hadith Takhrijاسناده صحيح اخرجه البيهقى 4 / 146 ۔ وفى المعرفة السنن والآثار له (2364) ۔ وعبد الرزاق (6976) ۔ و ابن أبي شيبة (10065)۔
It is narrated from Tawus that Ibn Abbas (may Allah be pleased with him) was asked about ambergris, so he said: If there is anything in it, then it is the fifth part.
Hadith Referenceمسند الإمام الشافعي / كتاب الزكاة / 734
Hadith Takhrijاسناده صحيح اخرجه البيهقى 4 / 146 ۔ وفى المعرفة السنن والآثار له (2364) ۔ وعبد الرزاق (6976) ۔ و ابن أبي شيبة (10065)۔