Section 3. His Confidence In The Midst of Danger.
‘I laid myself down and slept,
I awoke, for YHWH sustains me.
I will not be afraid of ten thousands of people,
Who have set themselves against me round about.'
So satisfied that YHWH had heard him he could now settle down to sleep. And in the morning he awoke, aware that he was still safe because YHWH was sustaining him. With that knowledge he would not be afraid of anyone, even ‘ten thousands' of people (a great army), even though they had surrounded him and were set against him.
The picture fits exactly into the circumstances. David in the camp, supported by his men, his faithful private army, together with others who had accompanied them, faced with the possibility of an approaching army of Israel surrounding the camp in order to destroy them, but no longer afraid because YHWH sustained him.