Saul said to Michal, “Why have you deceived me thus and let my enemy go, so that he has escaped?” And Michal answered Saul, “He said to me, ‘Let me go. Why should I kill you?’”
Here is, I. Saul's further design of mischief to David. When David had escaped the javelin, supposing he went straight to his own house, as indeed he did, Saul sent some of his guards after him to lay wait at the door of his house, and to assassinate him in the morning as soon as he stirred out, Sa1 19:11.
Commenting on 1 Samuel 19:11-17
And Saul said unto Michal,.... After the messengers returned and reported what they had seen, when Saul either came to her at her house, or sent for her to his palace: why hast thou deceived me so; for deceiving his messengers was deceiving him, by pretending David was sick and in bed, when she had placed an image there, and had let him down through...
Let me go; why should I kill thee? - That is, If thou do not let me go, I will kill thee. This she said to excuse herself to her father: as a wife she could do not less than favor the escape of her husband, being perfectly satisfied that there was no guilt in him.