There is an hour at night that no Muslim happens to be asking Allah, the Almighty, any good of this world or the Hereafter except that He will give it to him, and this occurs every night
Authentic hadithعن جابر رضي الله عنه قال: سمعت رسول الله صلى الله عليه وسلم يقول: «إن في الليل لساعة، لا يُوَافِقُهَا رجُلٌ مُسلم يَسأل الله تعالى خيرًا من أمْرِ الدنيا والآخرة، إلا أعْطَاه إِياه، وذلك كُلَّ ليلة».
Jābir (may Allah be pleased with him) reported: I heard the Messenger of Allah (may Allah's peace and blessings be upon him) saying: "There is an hour at night that no Muslim happens to be asking Allah, the Almighty, any good of this world or the Hereafter except that He will give it to him, and this occurs every night."
Explanation
Every night, there is a time when supplications are answered. No Muslim makes supplication during this time that does not involve something prohibited except that Allah answers it. It is the last third of the night as stated in other authentic texts.
Source · Narrated by Muslim
From the Hadith Encyclopedia (hadeethenc.com).