It is well known that the Lord descends in the last third of the night and Says: "‘Is there any seeker of forgiveness so that I would forgive for him? Is there anyone with a demand so that I would give him? Is there any repentant person so that I would accept his repentance?’ Until the rise of dawn." [Al-Bukhari and Muslim] This is the time during which the supplication is answered and when the slave is in prostration, he is even closer to his Lord and in a position that makes it more likely for his supplication to be fulfilled. This is because Allah The Almighty draws near His slave at the last third of the night and the slave becomes the closest to the Lord while he is in prostration. For this reason, the Messenger of Allah said: "I have been forbidden from reciting the Quran while bowing or prostrating. So, in bowing, exalt Allah The Exalted, and in prostration, be earnest in supplication, for you are in a position that entitles you to have your supplication answered.” [Muslim]
If those three conditions are realized: the slave is close to his Lord, and the Lord Is close to His slave, in the last third of the night when the supplication receives an answer, it is, most likely, that Allah The Almighty will respond to his supplication.
At the time of the Athaan (first call to prayer), and in the interval between the Athaan and the Iqaamah (second call to prayer), the supplication never fails to receive an answer according to an authentic Hadeeth (narration) with a Saheeh (sound) chain of narrators. The same is true of the time following the prescribed obligatory prayers, the time when the Imaam is ascending the pulpit (on Friday) until the prayer is over, and the last hour of Friday.
Those days, nights and hours (during which the supplication is answered) are honored for reasons, some of which are beyond human knowledge, and others are known to people.
In the last third of the night, the soul becomes pure, more sincere, and more devoted to Allah The Almighty. On Friday, the hearts of believers collaborate in good deeds to solicit the mercy of Allah The Almighty, which makes it more likely for the supplication to receive an answer. The same applies to the state of submissiveness of the heart and humiliation before the Lord Almighty.
This is the reason why ‘Umar, may Allah be pleased with him, did not rely, in terms of response, on the supplication itself so much as on opening the gate of supplication. He says, "If the gate of supplication is opened, this means that the gate of response will be opened." That is, when one is helped to supplicate in this manner where the heart is submissive, and one stands in humility before the Lord, singing His praises, imploring Him, humbly and tearfully, he should know that this supplication will receive an answer.
It is most likely that a supplication will be accepted by Allah The Almighty when one, being in the state of Tahaarah (ritual purity), faces the Qiblah (direction of prayer), raises his hands, and then supplicates in that state of submissiveness. This was the practice of the Messenger of Allah who used to raise his hands in supplication so much that the whiteness of his armpits would be visible, [Al-Bukhari and Muslim], just as the Prophet did in all his affairs. It was said in a Hadeeth (narration): "Whenever anything concerned him (the Prophet ), he would raise his head towards the sky; and whenever he strove in supplication, he would say: ‘Ya Hayy, Ya Qayyoom (O (Allah) The Ever-Living, The Sustainer of [all] existence).’"
If one faces Allah The Almighty and supplicates Him, raising his hands with humility, imploring Him humbly and tearfully and with a present heart, at those virtuous times, it is almost certain that his supplication will be accepted by Allah The Almighty.