Sa'id bin Jubayr narrates from Ibn Abbas (may Allah be pleased with them both) regarding this verse: "And do not have relations with them while you are in i'tikaf in the mosques" [Surah al-Baqarah: 187]: Mubasharah, mulamasah and mass all mean sexual intercourse, but Allah Almighty alludes to whatever He wills with whatever words He wills.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8597