Sahih al-Bukhari, Book 63, Hadith 100 (In-Book) ⓘ
Narrated Um Khalid bint Khalid: When I came from Ethiopia (to Medina), I was a young girl. Allah's Messenger made me wear a sheet having marks on it. Allah's Messenger was rubbing those marks with his hands saying, "Sanah! Sanah!" (i.e. good, good).
حَدَّثَنَا الْحُمَيْدِيُّ، حَدَّثَنَا سُفْيَانُ، حَدَّثَنَا إِسْحَاقُ بْنُ سَعِيدٍ السَّعِيدِيُّ، عَنْ أَبِيهِ، عَنْ أُمِّ خَالِدٍ بِنْتِ خَالِدٍ، قَالَتْ قَدِمْتُ مِنْ أَرْضِ الْحَبَشَةِ وَأَنَا جُوَيْرِيَةٌ، فَكَسَانِي رَسُولُ اللَّهِ صلى الله عليه وسلم خَمِيصَةً لَهَا أَعْلاَمٌ، فَجَعَلَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَمْسَحُ الأَعْلاَمَ بِيَدِهِ وَيَقُولُ " سَنَاهْ، سَنَاهْ " . قَالَ الْحُمَيْدِيُّ يَعْنِي حَسَنٌ حَسَنٌ.
also referenced under: Hadith 3874 (DarusSalam) & Volume 5, Book 58, Hadith 214 (USC-MSA)