Kings I 28:18

18 because thou didst not hearken to the voice of the Lord, and didst not execute his fierce anger upon Amalec, therefore the Lord has done this thing to thee this day.

Kings I 28:18 In-Context

16 And Samuel said, Why askest thou me, whereas the Lord has departed from thee, and taken part with thy neighbour?
17 And the Lord has done to thee, as the Lord spoke by me; and the Lord will rend thy kingdom out of thy hand, and will give it to thy neighbour David.
18 because thou didst not hearken to the voice of the Lord, and didst not execute his fierce anger upon Amalec, therefore the Lord has done this thing to thee this day.
19 And the Lord shall deliver Israel with thee into the hands of the Philistines, and to-morrow thou and thy sons with thee shall fall, and the Lord shall deliver the army of Israel into the hands of the Philistines.
20 And Saul instantly fell at his full length upon the earth, and was greatly afraid because of the words of Samuel; and there was no longer any strength in him, for he had eaten no bread all that day, and all that night.

The Brenton translation of the Septuagint is in the public domain.