I never heard the Prophet ﷺ say of anyone walking on the earth that he is among the people of Paradise, except for Abdullah bin Salam. He said, and concerning him this verse was revealed, "And a witness from the Children of Israel testified" [Ahqaf 46:10]. He said, I do not know, Malik said, whether this was part of the verse or part of the hadith.
ما سمعت النبي ﷺ يقول لأحد يمشي على الأرض: إنه من أهل الجنة إلا لعبد الله بن سلام قال، وفيه نزلت هذه الآية: {وشهد شاهد من بني إسرءيل} [الأحقاف: ١٠] قال: لا أدري، قال مالك: الآية، أو في الحديث.
Bukhari narrated it in the Virtues of the Ansar (3812), and Muslim in the Virtues of the Companions (2483), both from Malik, who related it from Abu Nadr, the freedman of Umar bin Ubaydullah, from Amir bin Saad bin Abu Waqqas, from his father, who said, and then he mentioned it. The wording given is Bukhari's, and Muslim did not mention "and concerning him it was revealed..." etc.Regarding his statement, "I have not heard the Prophet ﷺ say of anyone walking on earth..." it is known that Saad bin Abu Waqqas was aware that the Prophet ﷺ had said of a group of people that they were among the people of Paradise. The answer given is that he said this after the deaths of those who had been given glad tidings of Paradise, since Abdullah bin Salam lived on after them, and of the ten none remained with him except Saad and Saeed bin Zayd. This is supported by some wordings of the hadith, such as what appears in Muslim, "he says of a living person walking..." See, Fath al-Bari.