Abrogation of Recitation a Fact or a Myth

Tradition n. 8

(h) Zarr says: Ubayy b. Ka'b told me, O Zarr: "How much of Surah of al Ahzab do you read?" I said: "Seventy three verses". He said: "though it was equal to the Surah of al Baqarah, or it was longer than that"