How can my supplication be answered?.
Allah says in Ayat (55,56) of Surat Ala'raf {Call upon your Lord humbly and secretly, indeed, He does not like the aggressors, and Do not cause corruption on the earth after its reformation, and Call upon Him in fear and hope, indeed, the mercy of Allah is near of the good doers}, so Allah commanded His servants to call upon Him humbly and secretly, and to call upon Him in fear of His punishment and hope of His reward, so Single Him out of worship, Call upon Him in submission and humility of your hearts, and Do not raise your voices in supplication out of hypocrisy, indeed, Allah does not love the aggressors and the tyrants who transgress the limits of Allah in supplication or anything else, and as narrated by Abu Musa Alash'ari: "We were along with the Prophet (PBUH) on a journey, and the people began to pronounce Allahu Akbar: Allah is the Most Great, loudly, so the Prophet said O people! Show mercy to yourselves for you are not calling one who is deaf nor is He absent, indeed, you are calling One who is All-Hearing, Ever-Near, and is with you" (Sahih Muslim 2704 a).
One form of exceeding the limits in supplication (Dua') is asking for unnecessary conditions or restrictions, as Abu Na'amah narrated: "Abdullah bin Mughaffal heard his son praying to Allah O Allah! I ask You a white palace on the right of Paradise when I enter it, he said O my son! Ask Allah for Paradise and Seek refuge in Him from Hell for I heard the Messenger of Allah (PBUH) saying in this Ummah there will be some people who will transgress the limits in purification as well as in supplication" (Abu Dawood 96).
Another form of exceeding the limits in supplication is when a person asks for harm to come to Muslims or even to himself, his children, or his wealth, as Jabir bin Abdullah narrated that Allah's Messenger (PBUH) said: "Don't invoke curses on your own selves, or on your children or on your possessions lest you coincide with a moment when Allah is asked for giving and He answers you" (Sahih Muslim 3009).
Among the conditions for a supplication to be answered are that a person should not supplicate for something sinful, or for severing the ties of kinship, or be impatient for his supplication to be answered and gives up supplication, as Jabir bin Abdullah narrated that Allah's Messenger (PBUH) said: "there is none who utters supplication except that Allah gives him what he asked for, or prevents evil from him that is equal to it as long as he does not supplicate for evil or severing the ties of the womb" (Jami' Altirmidhi 3381), and as narrated by Abu Hurayrah that Allah's Messenger (PBUH) said: "The supplication of the servant is granted in case he does not supplicate for sin or for severing the ties of womb, or he does not become impatient, it was said Messenger of Allah! What does "if he does not grow impatient'' imply?, He said that he should say I supplicated and I supplicated but I did not find it being responded, and then he becomes frustrated and abandons supplication" (Sahih Muslim 2735 c).
Another condition for a supplication to be answered is that a person's earnings, food, drink, clothing must be from lawful sources, as Abu Hurayrah narrated that Allah's Messenger (PBUH) made a mention of a person who travels widely, his hair is disheveled, and he is covered with dust, he raises his hands to the sky and says O Lord! O Lord! Yet his food is from the unlawful, his drink is from the unlawful, his clothing is from the unlawful, and he was nourished by the unlawful, so How can that be accepted" (Sahih Muslim 1015).
Allah's Messenger (PBUH) sought refuge from the supplication that is not answered and is not taken into account for it is a sin or something that Allah does not approve, where was narrated by Zaid bin Arqam that Allah's Messenger said: "Allahumma ini a'auzu beka min elmin la yanfa-ou wa men qalbin la yakhsha-ou wa men nafsin la tashba-ou wa men da'watin la youstajabou laha: O Allah, I seek refuge in you from the knowledge which does not benefit, from the heart that does not entertain the fear, from the soul that does not feel contented and from the supplication that is not responded" (Sahih Muslim 2722).
It is recommended that the servant should supplicate frequently while prostrating, as Abu Hurayrah narrated that Allah's Messenger (PBUH): "The closest a servant comes to his Lord is when he is prostrating, so Supplicate frequently" (Sahih Muslim 482), and in another narration of Ibn Abbas that the Messenger of Allah (PBUH) said: "Indeed, I have been forbidden to recite the Quran in the state of bowing and prostration, as for bowing (Ruku'), Extol in it the Lord, the Almighty and Majestic, and as for prostration, Be earnest in supplication, for it is worthy that your supplications will be answered" (Sahih Muslim 479).