Is doubt concerning the answer to prayer, despite later acceptance of God's decree, considered a negative assumption about God?

The feeling that a supplication has not been answered is not considered a negative assumption about Allah Almighty, because the answer to a supplication takes different forms: either the supplication is answered quickly, or Allah stores it for the Hereafter, or He averts a similar evil with it. Allah may also not answer a supplication due to His wisdom and mercy, or due to an impediment to the answer on the part of the supplicant. This does not imply a negative assumption about Allah.