Mishkat al-Masabih 4030
Sa‘d b. Abu Waqqas said:
While I was sitting God’s Messenger gave a company something but omitted the one who was most attractive to me. I therefore got up and said, ‘Why have you omitted so and so? I swear by God that I consider him to be a believer.” God’s Messenger replied, “No, a Muslim.” Sa'd mentioned that three times and he gave him the same reply, then said, “I give a man something although I like someone else better, from fear he may be thrown face downwards in hell.” 

(Bukhari and Muslim.) In a version by both of them Zuhri said be considered that Islam is the attestation of belief and faith is good action.
وَعَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ قَالَ: أَعْطَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ رَهْطًا وَأَنَا جَالِسٌ فَتَرَكَ رَسُولُ اللَّهِ صلى الله عَلَيْهِ وَسلم مِنْهُم رَجُلًا وَهُوَ أَعْجَبُهُمْ إِلَيَّ فَقُمْتُ فَقُلْتُ: مَا لَكَ عَنْ فُلَانٍ؟ وَاللَّهِ إِنِّي لَأُرَاهُ مُؤْمِنًا فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أوْ مُسلما» ذكرَ سَعْدٌ ثَلَاثًا وَأَجَابَهُ بِمِثْلِ ذَلِكَ ثُمَّ قَالَ: «إِنِّي لَأُعْطِي الرَّجُلَ وَغَيْرُهُ أَحَبُّ إِلَيَّ مِنْهُ خَشْيَةَ أَنْ يُكَبَّ فِي النَّارِ عَلَى وَجْهِهِ» . مُتَّفَقٌ عَلَيْهِ. وَفِي رِوَايَةٍ لَهُمَا: قَالَ الزُّهْرِيُّ: فترى: أَن الْإِسْلَام الْكَلِمَة وَالْإِيمَان الْعَمَل الصَّالح