a watch: one of the fixed stretches the night was divided into, and so a way of telling time in the dark
Long before clocks, the night was cut into blocks and sentries stood duty in turn, each pair of eyes covering one block until the next shift took over. Israel counted three of them, which is why the Bible can speak of the middle one and of the last one before sunrise. This word names the block of time itself. It does not name the guards, and it does not name their duty, though all three come from the same root for keeping and guarding (שָׁמַר). Judges 7:19 puts the time word and the sentries side by side in one sentence: Gideon arrives at the start of the middle watch, just after the guards have been posted.
Because of that, the word is mostly a way of saying when something happened in the dark, and the moment it marks tends to be the turning point of a story:
- the LORD looks down on the Egyptian army in the morning watch, the last stretch before dawn (Exodus 14:24)
- Gideon reaches the edge of the camp at the beginning of the middle watch (Judges 7:19)
- Saul cuts into the enemy camp in the morning watch and fights on into the heat of the day (1 Samuel 11:11)
The poets take the same word into the plural and use it for the hours a person is awake while everyone else sleeps. It is the time for remembering God on the bed (Psalm 63:6), for waking ahead of the hour to sit with what God has promised (Psalm 119:148), and for rising to cry out over starving children (Lamentations 2:19). What the soldier counts as a shift, the person at prayer counts as a long dark stretch with God.
Once, in Psalm 90:4, the word becomes a measure of how briefly time passes. A thousand years look to God like yesterday once it is over, and like a watch in the night: a stretch of hours a sleeper passes through and never notices at all.