Bar (בָּר) carries a rich range of meanings: grain (especially wheat or threshed corn), purity/cleanness, and open country or wilderness. The same consonantal form appears in different contextual meanings throughout the Old Testament. When describing grain, it emphasizes abundance and provision. When meaning 'pure,' it emphasizes moral cleanness. Both senses are theologically significant.
Joseph stored up bar (grain) in Egypt to feed the world through famine — a powerful type of Christ, the bread of life who feeds the spiritually hungry. The 'pure heart' (bar lebab) of Psalm 24 and 73 describes the one who may ascend the LORD's holy hill. Psalm 2:12 commands kings to 'kiss the Son' — the Hebrew is 'kiss bar' — submit to the pure, anointed One.
The dual meaning of bar — grain and purity — creates a beautiful theological convergence: Christ is both the bread that sustains life and the pure, undefiled Son. Psalm 2:12's 'kiss the bar' (kiss the Son) joins submission to the pure Messiah with the provision imagery of grain. He who is the bread of life (John 6:35) is also the Son of absolute moral purity.