Ziyad related to me from Malik from Ibn Shihab that the Messenger of Allah ﷺ used to go to relieve himself in houses. Malik said, "Someone doing itikaf should not leave for his parents' funeral or for anything else."
أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَذْهَبُ لِحَاجَةِ الإِنْسَانِ فِي الْبُيُوتِ قَالَ مَالِكٌ لاَ يَخْرُجُ الْمُعْتَكِفُ مَعَ جَنَازَةِ أَبَوَيْهِ وَلاَ مَعَ غَيْرِهَا