Allah commands His servants to supplicate to Him, for this will ensure their welfare in this life and the Hereafter. Allah said,
ادْعُواْ رَبَّكُمْ تَضَرُّعًا وَخُفْيَةً
(Invoke your Lord Tadarru`an and Khufyah) meaning, in humbleness and humility. Allah said in a similar Ayah,
وَاذْكُر رَّبَّكَ فِي نَفْسِكَ
(And remember your Lord within yourself) 7:205 It is recorded in the Two Sahihs that Abu Musa Al-Ash`ari said, "The people raised their voices with supplications but the Messenger of Allah ﷺ said,
«أَيُّهَا النَّاسُ ارْبَعُوا عَلَى أَنْفُسِكُمْ فَإِنَّكُمْ لَا تَدْعُونَ أَصَمَّ وَلَا غَائِبًا إِنَّ الَّذِي تَدْعُونَ سَمِيعٌ قَرِيب»
(O people! Take it easy on yourselves. Verily, you are not calling one who is deaf or absent, rather, the One you are calling is All-Hearer, Near (to His servants by His knowledge).) Ibn Jarir said that,
تَضَرُّعًا
(Tadarru`an), means obeying Him in humility and humbleness,
وَخُفْيَةً
(and Khufyah), with the humbleness in your hearts and certainty of His Oneness and Lordship not supplicating loudly to show off.
It was reported that `Ata' Al-Khurasani narrated from Ibn `Abbas, who said about Allah's statement,
إِنَّهُ لاَ يُحِبُّ الْمُعْتَدِينَ
(He likes not the aggressors) "In the Du`a' and otherwise." Abu Mijlaz commented on,
إِنَّهُ لاَ يُحِبُّ الْمُعْتَدِينَ
(He likes not the aggressors), "Such (aggression) as asking to reach the grade of the Prophets." Imam Ahmad narrated that Abu Ni`amah said that `Abdullah bin Mughaffal heard his son supplicating, "O Allah! I ask you for the white castle on the right side of Paradise, if I enter it." So `Abdullah said, "O my son! Ask Allah for Paradise and seek refuge with Him from the Fire, for I heard the Messenger of Allah ﷺ saying,
«يَكُونُ قَوْمٌ يَعْتَدُونَ فِي الدُّعَاءِ وَالطَّهُور»
(There will come some people who transgress in supplication and purification)" Ibn Majah and Abu Dawud recorded this Hadith with a good chain that there is no harm in, and Allah knows best.
Allah said next,
وَلاَ تُفْسِدُواْ فِى الاٌّرْضِ بَعْدَ إِصْلَـحِهَا
(And do not do mischief on the earth, after it has been set in order) 5:56. Allah prohibits causing mischief on the earth, especially after it has been set in order. When the affairs are in order and then mischief occurs, it will cause maximum harm to the people; thus Allah forbids causing mischief and ordained worshipping Him, supplicating to Him, begging Him and being humble to Him. Allah said,
وَادْعُوهُ خَوْفًا وَطَمَعًا
(and invoke Him with fear and hope) fearing what He has of severe torment and hoping in what He has of tremendous reward. Allah then said,
إِنَّ رَحْمَتَ اللَّهِ قَرِيبٌ مِّنَ الْمُحْسِنِينَ
(Surely, Allah's mercy is (ever) near unto the good-doers) meaning, His mercy is for the good-doers who obey His commands and avoid what He prohibited. Allah said in another Ayah,
وَرَحْمَتِى وَسِعَتْ كُلَّ شَىْءٍ فَسَأَكْتُبُهَا لِلَّذِينَ يَتَّقُونَ
(And My mercy envelopes all things. That (mercy) I shall ordain for those who who have Taqwa.) 7:156. Matar Al-Warraq said, "Earn Allah's promise by obeying Him, for He ordained that His mercy is near to the good-doers. " Ibn Abi Hatim collected this statement.