It comes from Twitter, specifically Marc Spears of Y!Sports:
Free agent center Greg Oden to make decision next week picking from Sacramento, Miami, ATL, NO, San Antonio & Dallas, source told Y! Sports.— Marc J. Spears (@SpearsNBAYahoo) July 23, 2013
We just outlined the Hawks current roster and cap situation so we showed how the Hawks can still spend up to around 7M tops for a player, not that Oden is getting that kind of run, but it highlights the flexibility the Hawks have and how they are included in Oden's decision making process.
The Hawks already have Al Horford, Elton Brand and Paul Millsap under contract for next year, but the Hawks sure could use a legit seven footer, if Oden is able to play after spending considerable time on the sidelines with various injuries.
We said we would have to wait and see when DeMarre Carroll was officially signed before we knew the Hawks were done. Clearly they are not yet.
Also, according to a league source, the Hawks have yet to free up some of that cap space by releasing the cap holds of Ivan Johnson and Anthony Tolliver and releasing the non-guaranteed contract of DeShawn Stevenson, but should Oden choose the Hawks, it's likely that some of those transactions would have to occur to make it so.