What is the meaning of Ibn Mas'ud's statement: "From the old ones of the first generation"?

Question : This is also a second question from Abd al-Rahman al-Bam. Where is he? Yes. He says: Al-Bukhari narrated from Abdullah ibn Mas'ud: "Surat al-Bani Isra'il, al-Kahf, Maryam, Ta-Ha, and al-Anbiya. These are what? What? From the old ones of the first generation, and they are from my old ones. So what is the meaning of 'from the old ones of the first generation'?"

Answer : It means that he memorized them long ago. That is why he said, "They are from my old ones." The origin of the word "old" (tilad) is its root. Did you understand?