It repenteth me that I have set up Saul to be king
Which is not to be understood of any change of mind, counsel, purpose, or decree in God, which is not consistent with his unchangeable nature; but of a change of dispensation, and outward dealings, and is spoken after the manner of men, who, when they repent of anything, change the course of their conduct and behaviour; and so the Lord does without any change of his mind and will, which alters not; and though he changes the outward dispensations of his providence, yet he never changes and alters in the matters and methods of his grace; though he repented he made Saul king, he never repents of his making his saints kings and priests for himself; his outward gifts he sometimes takes away, as an earthly crown and kingdom; but his gifts and calling, which are of special grace, are without repentance, (See Gill on Genesis 6:6).
for he is turned back from following me;
from after my worship, as the Targum, from doing his will and work:
and hath not performed my commandments:
particularly in this affair relating to Amalek:
and it grieved Samuel;
that Saul should so soon be rejected from being king, and that he should do anything to deserve it; and whom Samuel had anointed king, and for whom he had a cordial respect, and to whom he wished well, both for his own personal good, and for the good of the people of Israel; so far was he from rejoicing at his fall, who came in his stead, and to whom he gave way in the affair of government:
and he cried unto the Lord all night;
or prayed, as the Targum; either that the Lord would inform him of the particulars wherein Saul had done amiss, or that he would forgive his sin, and not reject him from the kingdom.