Shared ground
These two verses remember words spoken during a crisis. The speaker connects inner conviction (“I believed”) to outward speech (“therefore I said”), and then quotes what was said at the time: a frank admission of being “greatly afflicted” (v.10). The next verse quotes a second crisis statement, explicitly marked as said “in my haste” (v.11), which suggests pressure, panic, or a rushed conclusion.
The text also distinguishes two kinds of speech preserved from the same hard moment: honest reporting of suffering, and a sweeping judgment about other people (“All men are liars”). Even without adding anything beyond the lines themselves, the psalm treats remembered speech as something that can be replayed and weighed later.
Where interpretation differs
One difference is what “I believed” is mainly about. Some read it as trust in God in the middle of distress, so the speech that follows is a faith-shaped cry. Others read it more as confidence in the truth of the speaker’s testimony—“I was convinced this was real, so I said it”—without specifying the object of belief.
A second difference is how literally to take “All men are liars.” Some read it as a deliberately universal statement about human unreliability (in that moment, nobody could be trusted). Others read it as intentional exaggeration born from disappointment, with “all” functioning like emotional overstatement rather than a settled claim about every person.
Why the disagreement exists
The verse gives no explicit object for “believed,” and the connector (“therefore”) can be heard as linking belief either to lament in the moment or to testimony when looking back. Likewise, “in my haste” signals that the speaker later views the statement as rushed, but it does not spell out whether the content (“all men are liars”) is fully true, partly true, or simply too broad.
What this passage clearly contributes
Explicitly, the passage shows (1) belief and speech are linked (“I believed, therefore I said”), (2) faith does not erase affliction but can coexist with it (“I was greatly afflicted”), and (3) crisis can produce fast, sweeping claims about people (“in my haste… ‘All men are liars’”). As part of Psalm 116’s larger thanksgiving, these remembered lines help explain what the speaker sounded like before deliverance and why later gratitude is meaningful (Psalm 116:10–11).