Reference: Siyar A’laam an-Nubalaa – Volume 5, Page 583
Ibn Jurayj reports on the authority of ‘Ataa ibn Abee Rabaah:
When a man narrates to me a hadeeth, I remain silent [to encourage] him – [giving the impression] as if I haven’t heard it [before], even though I [first] heard it before he was even born!