1 Samuel 21:12

10 That day David fled from Saul and went to Achish king of Gath.

11 But the servants of Achish said to him, “Is this not David, the king of the land? Did they not sing about him in their dances, saying: ‘Saul has slain his thousands, and David his tens of thousands’?”

Now David took these words to heart and was very much afraid of Achish the king of Gath.

13 So he changed his behavior before them and feigned madness in their hands; he scratched on the doors of the gate and let his saliva run down his beard.

14 Then Achish said to his servants, “Look, you can see that the man is insane! Why have you brought him to me?

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
Now David took these words to heart and was very much afraid of Achish the king of Gath.
KJV
And David laid up these words in his heart, and was sore afraid of Achish the king of Gath.
WEB
David laid up these words in his heart, and was very afraid of Achish the king of Gath.
ASV
And David laid up these words in his heart, and was sore afraid of Achish the king of Gath.
DARBY
And David took to heart these words, and was much afraid of Achish the king of Gath.
BLB
And David set these words in his heart, and he was exceedingly afraid of Achish king of Gath.
ÅB
David la seg disse ord på hjerte og var svært redd Akis, kongen i Gat.
OTB
David tenkte over disse ordene og ble svært redd for Akisj, kongen av Gat.
B1930
David la sig disse ord på hjerte og var svært redd Akis, kongen i Gat.

Study notes (Tyndale)

Original text and word study

Cross references