Hadith 4:100
She said that Abu Bakr kissed the Prophet when he was dead. Tirmidhi and Ibn Majah transmitted it.
وَعَن عَائِشَةَ قَالَتْ: إِنَّ أَبَا بَكْرٍ قَبَّلَ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ مَيِّتٌ. رَوَاهُ التِّرْمِذِيّ وَابْن مَاجَه
Original Reference: Mishkat al-Masabih 1624