When Abu Huraira accompanied by his slave came intending to embrace Islam, they lost each other on the way. (When the slave showed up) Abu Huraira said (to the Prophet), "I make you witness that the slave is free for Allah's Cause."
لَمَّا أَقْبَلَ أَبُو هُرَيْرَةَ ؓ وَمَعَهُ غُلاَمُهُ وَهْوَ يَطْلُبُ الإِسْلاَمَ فَأَضَلَّ أَحَدُهُمَا صَاحِبَهُ بِهَذَا وَقَالَ أَمَا إِنِّي أُشْهِدُكَ أَنَّهُ لِلَّهِ