John Gill Commentary 2 Samuel 14:12

"Then the woman said, Let thy handmaid, I pray thee, speak a word unto my lord the king. And he said, Say on." — 2 Samuel 14:12 (ASV)

Then the woman said, let your handmaid, I pray you, speak
[one] word unto my Lord the king
Having gained her point, and gotten a decree from him confirmed by an oath, that her son though he had killed his brother should not die; she proceeds to accommodate the parable, and apply it to the case of Absalom, and improve it in his favour:

and he said, say on ;
gave her leave to say what she had further to observe to him; see (Luke 7:40) .