To the Calvinist who believes that 1 Sam 15 is a good prooftext for immutability:

1Sa 15:29 And also the Strength of Israel will not lie nor relent. For He is not a man, that He should relent.”

Is it possible that 1 Sam 15:29 is limited to the context (God is saying He will not repent of repenting of making Saul king) and that 1Sa 15:35 and 1Sa 15:11 better describe God’s thoughts and actions as described in the chapter?