Authentic
graded by Al-Albani
Mishkat al-Masabih 6209
وَعَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ قَالَ: مَا سَمِعْتُ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ لِأَحَدٍ يَمْشِي عَلَى وَجْهِ الْأَرْضِ «إِنَّهُ مِنْ أَهْلِ الْجَنَّةِ» إِلَّا لِعَبْدِ اللَّهِ بن سَلام. مُتَّفق عَلَيْهِ
Sa'd b. Abu Waqqas said:
I have not heard the Prophet say to anyone who walked on the face of the earth that he would be one of the inhabitants of paradise, except 'Abdallah b. Salam. (Bukhari and Muslim.)
Cited in Mishkat al-Masabih (No. 6209).