good question. and i have a straightforward answer: i don't know. i have this book 'munaDHarat ibn taymiyyah' and it refers to this debate being 'reliably' reported. i began searching for it in ibn kathir's al-bidayah wa'n nihayah but couldn't find it. i tried Husn al-Muhadarah, but no luck. ibn kathir did not even mention that imam ibn `aTaAllah passed away in 709. check out the wafyat section of 709AH. no mention of ahmed ibn Muhammad ibn `aTaAllah. it is mentioned however, that debates took place and ibn kathir is biased towards ibn taymiyyah. he criticizes one ibn `aTa of leveling charges against ibn taymiyyah, none of which according to ibn kathir were true. this ibn `aTa is ambiguous - because there was another ibn `aTa al-Hanafi who was against ibn taymiyyah. if ibn kathir is referring to imam ibn `aTaAllah, then surely his prejudice is obvious. anyway, ibn kathir - inspite of his standing - fails in being judicious when it comes to ibn taymiyyah. may Allah forgive him and have mercy on him. [the reason why i say he was injudicious is because he is himself an ash`ari and aids the cause prominently in his tafsir - including ziyarah and sifat. those who opposed ibn taymiyyah was because of it, not because they envied ibn taymiyyah.] -------- the debate is in itself useful even though it might be fictitious [i don't know]. i am myself in the process of ascertaining the source but i made haste in posting it, trusting shaykh hisham's references in the english article. he gives the following references which i shall cross-check, inshaAllah once i am free. until then, i will edit my original post such that it does not give a wrong impression that i have seen it. from shaykh hisham's article and its footnote: "From Usul al-Wusul by Muhammad Zaki Ibrahim Ibn Kathir, Ibn al-Athir, and other authors of biographical dictionaries and biographies have transmitted to us this authentic historical debate"  Footnote: See Ibn al-`Imad, Shadharat al-dhahab (1350/1931) 6:20f.; al- Zirikly, al-A`lam (1405/1984) 1:221; Ibn Hajar, al-Durar al-kamina (1348/1929) 1:148-273; Al-Maqrizi, Kitab al-suluk (1934-1958) 2:40-94; Ibn Kathir, al-Bidaya wa al-nihaya (1351/1932) 14:45; Subki, Tabaqat al-shafi`iyya (1324/1906) 5:177f. and 9:23f.; Suyuti, Husn al-muhadara fi akhbar misr wa al-qahira (1299/) 1:301; al-Dawadari, al-Durr al-fakhir fi sirat al-malik al-Nasir (1960) p. 200f.; al-Yafi`i, Mir'at al-janan (1337/1918) 4:246; Sha`rani, al-Tabaqat al-kubra (1355/1936) 2:19f.; al-Nabahani, Jami` karamat al-awliya' (1381/1962) 2:25f. ----------------------- here shaykh hisham might either be saying that a general mention of the debate took place or that the debate is reported entirely in one of these books. so the first one to check it and post it here gets four stars Allah ta'ala knows best.