Did the Asharis say its possible God can break His promises/threats? If so, How can this be so if breaking a promise is considered a bad quality when applied to humans? Does Surah Hajj 22:47 imply that Hell is a promise that can’t be broken?
No one among Ahl al-Sunna, i.e. Maturidis and Ash`aris, ever said that Allah can break his promises of reward. As for threats of punishment it is the very same case when it comes to the punishment of unbelievers as in al-Hajj 22:47, they are absolutely inevitable for them without fail, but at the time Allah sees fit. However, when it comes to the punishment of the sinful believers, i.e. any sin other than unbelief, Allah reserved to Himself the decision of either punishing them as threatened, out of His justice, or forgiving them because of their belief, out of His mercy. That is also the position of the totality of Ahl al-Sunna.
Hajj Gibril Haddad