A black woman used to sweep the mosque, and the Messenger of Allah ﷺ missed her. He asked about her after some days, and was told that she had died.He said, "Why did you not inform me?"Then he went to her grave and prayed over her.
حدثنا أحمد بن عبدة أنبأنا حماد بن زيد حدثنا ثابت عن أبي رافع
أن امرأة سوداء كانت تقم المسجد ففقدها رسول الله ﷺ فسأل عنها بعد أيام فقيل له إنها ماتت قال فهلا آذنتموني فأتى قبرها فصلى عليها
Bukhari narrated it, Prayer, chapter on sweeping the masjid and picking up rags, dirt, and twigs, no. 458, and others, and Muslim, Funerals, chapter on praying over a grave, no. 956, from the hadith of Hammad bin Zayd through this same chain.