Imam Ibrahim Nakha'i (may Allah have mercy on him) said: A menstruating woman’s husband may have intercourse with her in a soft place and between the thighs; if semen is discharged, she should wash that area and the man should perform ghusl (ritual bath).
Hadith Referenceسنن دارمي / من كتاب الطهارة / 1070
Hadith Takhrijاس قول کی سند صحیح ہے، لیکن کہیں اور نہ مل سکی۔ اس کے ہم معنی روایت [مصنف عبدالرزاق 971] میں ہے۔ نیز ابن ابی زائده: یحییٰ بن زکریا اور حماد: ابن ابی سلیمان ہیں۔
Brief Explanation
(Commentary on Ahadith 1067 to 1070)
«مراق»: It refers to the soft area which is located beneath the pelvis, and «دفق» means "he ejaculated," that is, ejaculation occurs. And "mubasharat" (مباشرت) refers to the act of bringing bodies into contact and clinging together.