Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
darimi:1038Sahl b. Ḥammād > Shuʿbah > Sayyār > Abū Wāʾil

[Machine] It is said that the one who is sexually impure (junub) or menstruating (hayid) should not recite, and one should not recite in the bathroom. And there are two situations in which a person should not mention Allah: when relieving oneself and during sexual intercourse. However, when a man comes to his family, he should start by saying "Bismillah" (In the name of Allah).  

الدارمي:١٠٣٨أَخْبَرَنَا سَهْلُ بْنُ حَمَّادٍ حَدَّثَنَا شُعْبَةُ عَنْ سَيَّارٍ عَنْ أَبِي وَائِلٍ قَالَ كَانَ

يُقَالُ لَا يَقْرَأُ الْجُنُبُ وَلَا الْحَائِضُ وَلَا يُقْرَأُ فِي الْحَمَّامِ وَحَالَانِ لَا يَذْكُرُ الْعَبْدُ فِيهِمَا اللَّهَ عِنْدَ الْخَلَاءِ وَعِنْدَ الْجِمَاعِ إِلَّا أَنَّ الرَّجُلَ إِذَا أَتَى أَهْلَهُ بَدَأَ فَسَمَّى اللَّهَ