How important it is that Allah RESPONDS and GRANTS your dua, GUARANTEED?

It appears in the Prophet’s Sunnah on a number of occasions, pertaining to Allah’s
greatest name,  where Buraydah b. al-Husayb relates that Rasulullah salla Allahu alaihi wa sallam heard a man beseeching his Rabb in the following words:

“O Allah! I beseech You by affirming that You are Allah, there is no god besides You, the One, the self-subsisting, who begets not and is not begotten, and who no one else resembles in any way.”

After Rasulullah salla Allahu alaihi wa sallam heard this, he said: “I swear by Him in whose hand is my soul, this man has beseeched Allah with His greatest name, which if anyone supplicates with it, that supplication will be accepted, and if anyone asks by it, it will be granted.”

[Sunan al-Tirmidhi (3475),
Sunan Abi Ddwtid (1493) and
Sunan Ibn M4Jah (3857)]