A delayed response to our du’as reminds us that Allah is al-Malik, the King and Owner of All Kingdoms. No one can interfere in His Decisions, and no one can question His resolutions. As Allah says in the Qur’an:
“He is not questioned regarding what He does, but rather they are questioned (regarding what they do).” (Surah al-Anbiya:23)
He also says:
“And Allah Judges, and there is none that can change His Judgement. And He is the Ever-Swift in Reckoning.” (Surah al-Rad:41)
So the true Muslim should not question the Will of Allah, rather he accepts it, and is pleased with it.
As one of the scholars wrote: “So there is none of us who can escape from the Will of Allah and His Decree. And no one can avert His Judgment or His Trials (upon us). Verily, we all belong to Allah, and we are His slaves and (part of His) possessions. He does with us as He pleases, and what He wills.” (Al-Hamad)