Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Prophet (peace and blessings be upon him) "forbade two sales in one sale."
(b) In the narration of Yahya: the Messenger of Allah (peace and blessings be upon him) "forbade two sales in one sale." Abd al-Wahhab says: (That is,) it is yours for ten in cash and twenty on credit.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10878