Bochan refers to a tested or proved stone — an assay stone used to test the purity of metals, or metaphorically a stone that has itself been proven and found trustworthy. It appears in Isaiah 28:16 in one of Scripture's most significant messianic passages: 'I lay in Zion a stone, a tried stone (eben bochan), a precious cornerstone, a sure foundation.' The word comes from the root bachan (H974), to test or examine.
Bochan carries dual meaning — a stone that tests others, and a stone that has itself been tested. In Isaiah 28, God lays in Zion a foundation stone that is bochan — both proven reliable and the standard by which everything else is measured. The New Testament identifies this stone as Christ (1 Pet 2:6; Rom 9:33). Jesus is the One who has passed through every test — temptation, suffering, death — and has been vindicated as the trustworthy foundation of God's kingdom.