Moses
Genesis 20:9BSB·traditional attribution

Then Abimelech called Abraham and asked, “What have you done to us? How have I sinned against you, that you have brought such tremendous guilt upon me and my kingdom? You have done things to me that should not be done.”

John Calvin Reformed @genevareformer

9. Then Abimelech called Abraham . There are those who suppose that the king of Gerar did not make a complaint against Abraham; but rather declared his own repentance. If, however we fairly weigh his words we find confession mixed with expostulation. Although he complains that Abraham had acted unjustly, he yet does not so transfer the blame to him, as to free himself from all fault.

Matthew Henry Presbyterian @wholebiblehenry

Abimelech, being thus warned of God in a dream, takes the warning, and, as one truly afraid of sin and its consequences, he rises early to obey the directions given him. I. He has a caution for his servants, Gen 20:8. Abraham himself could not be more careful than he was to command his household in this matter.

Commenting on Genesis 20:8-13

John Gill Reformed Baptist @doctorgill

Then Abimelech called Abraham,.... Who might be in the king's palace, being taken into it caressed by the king for the sake of Sarah: and said unto him; not in a passion, as might have been expected, but in a mild and gentle manner, yet with great strength of reasoning, and making very just expostulations with him: what hast thou done unto us?