Musannaf Ibn Abi Shaybah 24734 — Earnest money in a sale

It is narrated from Abd al-Rahman bin Farrukh that Sayyiduna Nafi' bin Abd al-Harith (may Allah be pleased with him) bought the prison house from Sayyiduna Safwan bin Umayyah (may Allah be pleased with him) for four thousand dirhams, on the condition that if Sayyiduna Umar (may Allah be pleased with him) approved, the sale would stand, and if Sayyiduna Umar (may Allah be pleased with him) did not approve, four hundred dirhams would belong to Safwan.