Question: Is it permissible for the traveller to have sexual intercourse with his wife during the day of Ramadhaan?
Response: In the Name of Allaah and all Praise is for Allaah. If he were a traveller or suffering from an illness which permitted him to break his fast then there is no expiation nor problem for him but, instead, it is for him to make up the day for which he had sexual intercourse with his wife. This is because the traveller and the one who is ill are permitted to break the fast, engage in sexual intercourse and the like of this. Allaah (subhaanahu wa-ta’aala) has said: {(Fasting) for a fixed number of days, but if any of you is ill or on a journey, the same number (should be made up) from other days. And as for those who can fast with difficulty (e.g. an old man, etc.), they have (a choice either to fast or) feed a poor person (for every day). But whoever does good of his own accord, it is better for him. And that you fast, it is better for you if only you know}, [Soorah al-Baqarah, Aayah 184]. The ruling for the woman in this regard is the (same) ruling (as) for the man. So, if she were travelling or suffering from an illness which made it difficult for her to fast, there would be no expiation for her to carry out.
Shaykh Ibn Baaz
Fataawa Ramadhaan – Volume 2, Page 439, Fatwa No.363.fatwaonline.com
