Urwah bin Zubair narrates: I went to Marwan bin Hakam and there we began to discuss in which situations ablution (wudu) becomes obligatory. So Marwan informed me that Lady Busrah bint Safwan (may Allah be pleased with her) told him this matter; she heard the Prophet Muhammad (peace be upon him) say: "When a person touches his private part, he should perform ablution." (Imam Ibn Hibban, may Allah have mercy on him, says:) We seek Allah's refuge from narrating in our books any such narration which has been transmitted by Marwan bin Hakam or people like him. The reason is, we do not consider it permissible to use unauthentic narrations as evidence, even if they support our own position, and among the schools of thought, we will only act upon those narrations which are authentic, even if they go against the statements of our own Imams. As for the narration transmitted by Lady Busrah (may Allah be pleased with her), as we have mentioned earlier, Urwah bin Zubair heard this narration from Lady Busrah (may Allah be pleased with her) through Marwan bin Hakam, but he was not satisfied with this, until Marwan sent one of his soldiers to Lady Busrah (may Allah be pleased with her) and he asked her. Then he went to those people and informed them about what Lady Busrah (may Allah be pleased with her) had stated. So Urwah heard this narration a second time from Lady Busrah (may Allah be pleased with her) through the soldier, but still he was not satisfied, until he himself went to Lady Busrah (may Allah be pleased with her) and heard this hadith from her. Thus, this narration is transmitted from Lady Busrah (may Allah be pleased with her) through Urwah. This is connected, it is not disconnected. Marwan and his soldier are two temporary narrators who have been omitted from the chain.