It is reported from Salim and Sulayman bin Yasar (may Allah have mercy on them both) that they were both asked about the menstruating woman: May her husband have intercourse with her when she sees the purity, before she takes a ritual bath? They said: No, not until she takes a ritual bath.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1485