You woke at the same hour again, wide awake for no reason you can name, and somewhere a voice asked whether it means something. The internet has a hundred answers, most of them confident and none of them from the Bible.
Here is the honest version. Scripture never assigns a meaning to three o'clock. It does say a great deal about people who were awake in the night, what they did with the hour, and how God met them there. That is the better question: not what the hour means, but what to do with it.
What the Bible says about the night watches
8 And the LORD called Samuel again the third time. And he arose and went to Eli, and said, Here am I; for thou didst call me. And Eli perceived that the LORD had called the child. 9 Therefore Eli said unto Samuel, Go, lie down: and it shall be, if he call thee, that thou shalt say, Speak, LORD; for thy servant heareth. So Samuel went and lay down in his place. 10 And the LORD came, and stood, and called as at other times, Samuel, Samuel. Then Samuel answered, Speak; for thy servant heareth.
The one clear case of God speaking in the night to a sleeper, and notice the shape of it: Samuel hears his name three times before anyone tells him what is happening, and the whole answer he is asked to give is "Speak; for thy servant heareth." If you want a prayer for the hour, that is it.
62 At midnight I will rise to give thanks unto thee because of thy righteous judgments.
The psalmist rises at midnight on purpose, to give thanks. Waking is not treated as a message to decode. It is treated as an appointment.
7 I will bless the LORD, who hath given me counsel: my reins also instruct me in the night seasons.
Instruction in the night seasons, David says, comes through his own inmost thoughts, with the Lord as counsellor. The night can be where you finally hear what you already know.
6 When I remember thee upon my bed, and meditate on thee in the night watches.
Remembering God on the bed, in the night watches. The pattern in the psalms is consistent: the sleepless hour is for remembering and meditating, not for reading signs.
2 It is vain for you to rise up early, to sit up late, to eat the bread of sorrows: for so he giveth his beloved sleep.
A caution against the other reading, that God wants you up and striving. Rising early and sitting up late to eat the bread of sorrows is named as vain, and sleep is named as his gift. Sometimes the message of the hour is: go back to sleep.
19 Arise, cry out in the night: in the beginning of the watches pour out thine heart like water before the face of the Lord: lift up thy hands toward him for the life of thy young children, that faint for hunger in the top of every street.
Jeremiah tells the ruined city to rise in the night and pour out its heart like water. If something is heavy, the night is a legitimate time to say so, out loud, all of it.
35 And in the morning, rising up a great while before day, he went out, and departed into a solitary place, and there prayed.
Jesus himself rose a great while before day to pray alone. If you are awake and cannot fix it, you are keeping the hours he kept.
So what is God trying to tell you at 3 a.m.? The Bible's answer is quieter than the internet's. He is not sending a code. He is available, the way he was to Samuel and to David, and the hour is yours to spend with him or to spend worrying.
Practically: sit up, say Samuel's line, read one psalm, and lie back down. If sleep does not come, put the livestream on low and let it read to you. If the waking keeps happening night after night, talk to a doctor as well as to God. The Bible has no quarrel with that.
Questions
Does the Bible say anything about 3 a.m. specifically?
No. No verse names three o'clock. The Bible speaks of night watches and of people who rose at midnight or before dawn to pray, but it never attaches a meaning to a particular hour.
Is waking up at 3 a.m. a spiritual attack?
Scripture does not teach that a waking hour is an attack. It does teach that the night is a time God meets people (Samuel, David, Jesus before dawn) and a time for pouring out the heart. Treat the hour as an invitation, not a threat, and if it keeps happening, see a doctor too.
What should I pray when I wake up at 3 a.m.?
Samuel's prayer is enough: "Speak; for thy servant heareth." Then Psalm 4:8. Then nothing. Silence counts.