New Defender's Study Bible Notes
26:25 builded an altar. According to records, this is the only altar built by Isaac. God appeared to him again after he was back at Beer-sheba (“well of the covenant”), where he had lived in his closest fellowship with God. The well had belonged to Abraham, and it was accepted as such by the Philistines (still a relatively small body of settlers that had come from their own homeland in Crete), so Isaac knew he was now justified in staying there. The ancient town of Beer-sheba has been partially excavated, and visitors today are shown a well claimed to be that of Abraham and Isaac.