Hadith.5541 - Hammad narrated from Al-Halabi from Abu Abdullah (as), who said
'I asked Imam (as) about a man who acknowledges a debt to one of his heirs.'
Imam (as) said: "It is permissible if he is solvent (financially capable)."
Al-Kāfi #160“I once asked abu ‘Abd Allah (a.s.), about the case of a man who in his illness at the time of his death confirms his owing a certain amount...
Al-Kāfi #163“About the case of a man who dies and a certain one of his heir confirms his owing a certain amount. He (the Imam) said, ‘It become binding...