The Last Third of the Night
Question :
When exactly is the precious last third of the night?
Answer:
It is not possible to limit the exact time, but it is still possible to know when the last third of the night begins. Since sunset is when the night begins and dawn is when it ends, you can break the time between the two into three equal parts. When the first two parts expire, then the last third of the night has begun. It is confirmed in the Two Sahihs that Abu Hurairah, may Allah be pleased with him, related that the Prophet ﷺ that, said :
"Allah Almighty descends every night to the lowest heaven, when one third of the night remains; then He Almighty says, "Who is supplicating to Me, and I will answer him; who asks from Me, and I will give to him; who asks forgiveness from Me, and I will forgive him."
Every Muslim should strive to benefit from the last third of the night, by praying and supplicating during at least a portion of it - perhaps that we achieve the blessings that are mentioned in the last Hadith, a gift from Allah Almighty, a prayer that is answered by us getting what we asked for. We ask Allâh to guide all Muslims.
Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 8 Page 410