In Maha Buddhavamsa The Great Chronicle of The Buddhas by Tipitakadhara Mingun Sayadaw, page 949 to 980, there is a series of question between the Buddha and Sakkra. This seems very relevant to the Buddhist meditation practice. Which Suttas does this conversation appear in?
2 Answers
Sakka-pañha Sutta: Sakka's Questions.
http://www.accesstoinsight.org/tipitaka/dn/dn.21.2x.than.html
As per the Story of the Youth Magha... It is found in the Dhammapada Commentary – in Book II. Heedfulness, Appamāda Vagga. Under that chapter II. 7. Is about “How Magha Became Sakka”.
You could also read about it HERE