Sulayman bin Yasar reports from one of the Companions (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) kept the qasamah as it had been in the Jahiliyyah.
In one hadith it is also stated that he (peace and blessings be upon him) judged by it in the claim of murder that the Ansar made against the Jews.
This statement is general, and what is meant by it is the number of oaths, for we have narrated through sound routes from Sayyiduna Sahl bin Abi Hathmah (may Allah be pleased with him) and others of the Ansar how his judgement between them was carried out, so it is necessary to follow that. And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب القسامة / 16467