thou shalt go down. This was the beginning of organised rising against the Philistines. All directed by God through Samuel; not by Saul.
behold. Figure of speech Asterismos. App-6.
offer. offer up. App-43.
sacrifice. slay. App-43. Note the Figure of speech Polysyndeton in 1 Samuel 10:8. App-6.
a another. different.