A woman and man who disagree over the immediate portion of the mahr

Abd al-A'la (may Allah have mercy on him) was asked: A man married a woman for a prompt and a deferred dowry, and he also consummated the marriage with her, but the woman claimed that he had not yet paid the prompt dowry. Abd al-A'la (may Allah have mercy on him) said: Sa'id (may Allah have mercy on him) narrated from Qatadah (may Allah have mercy on him) that he used to say: Regarding the prompt dowry, the burden of proof lies on her, that such-and-such an amount still remains owed by him; and his consummation of the marriage with her is a discharge (of the prompt dowry).

Al-Hasan (may Allah have mercy on him) used to say: The burden of proof (regarding the prompt dowry) lies on the man.