The eating of garlic or other (bad smelling vegetables).
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا عَبْدُ الْوَارِثِ، عَنْ عَبْدِ الْعَزِيزِ، قَالَ قِيلَ لأَنَسٍ مَا سَمِعْتَ النَّبِيَّ صلى الله عليه وسلم فِي الثُّومِ فَقَالَ " مَنْ أَكَلَ فَلاَ يَقْرَبَنَّ مَسْجِدَنَا ".
Narrated `Abdul `Aziz: It was said to Anas "What did you hear the Prophet (ﷺ) saying about garlic?" Anas replied, "Whoever has eaten (garlic) should not approach our mosque."