قَالَ مَالِكٌ : وَلَا بَأْسَ بِلَحْمِ الْحِيتَانِ، بِلَحْمِ الْإِبِلِ وَالْبَقَرِ وَالْغَنَمِ، وَمَا أَشْبَهَ ذَلِكَ مِنَ الْوُحُوشِ كُلِّهَا، اثْنَيْنِ بِوَاحِدٍ وَأَكْثَرَ مِنْ ذَلِكَ يَدًا بِيَدٍ، فَإِنْ دَخَلَ ذَلِكَ الْأَجَلُ فَلَا خَيْرَ فِيهِ. ¤
Imam Malik, may Allah have mercy on him, said that if the meat of fish is sold in exchange for the meat of camel, cow, or goat, whether more or less, there is no objection to it. However, it is necessary that the transaction be hand to hand (immediate payment), and not on credit.