Good luck from everything initially taught about a one-time capital of Egypt (3,3,4)
I believe the answer is:
all the best
'good luck' is the definition.
(I've seen this before)
'everything initially taught about a one-time capital of egypt' is the wordplay.
'everything' becomes 'all' (all things).
'initially' says to take the initial letters.
'about' is a charade indicator (letters next to each other).
'a one-time capital of egypt' becomes 'thebes' (I can't explain this - if you can you should believe this answer much more).
The first letter of 'taught' is 't'.
't' after 'thebes' is 'thebest'.
'all'+'thebest'='ALL THE BEST'
'from' is the link.
Can you help me to learn more?
(Other definitions for all the best that I've seen before include "Cheers" , "Without exception, unsurpassed" , "flower, every bit of it?" , "needing good luck!" , "A greeting" .)