ḥaphas

At its core this verb is about a determined, thorough search, the kind that turns a place over or hunts a person down until what is concealed is found. It is stronger than a casual look. Laban ransacks a whole camp for his stolen images, a steward opens every sack from oldest to youngest, and God vows to hunt fugitives out of the depths of the sea or the top of a mountain.

The same verb reaches inward. To search one's own heart or examine one's ways is to apply that thoroughness to oneself, and the poet pictures God's lamp searching the innermost person. Because the object can be almost anything hidden (a lost item, a fleeing enemy, buried wisdom, a secret scheme), English translators rotate among search, search out, seek, and ransack depending on what is being looked for.

What holds these uses together is the act of ferreting out what is not on the surface. When the thing sought is good, it is diligent pursuit; when it is a person in flight, it is a manhunt; when it is a plot, it shades into devising.

This is the reflexive twist of the same root: to make oneself into something that has to be searched for, that is, to hide in plain sight by altering one's appearance. It is always a deliberate act, and in the narratives it is always a king or a prophet trying to pass unseen. Saul puts on other clothes to visit the medium at night, a prophet masks his face with a bandage, and Ahab strips off his royal robes to enter battle unrecognized (a disguise that fails when a random arrow finds him anyway). Josiah does the same before the fatal battle at Megiddo.

The link back to the searching sense is real but not obvious, which is why the connection is debated. The everyday reader should simply note that one Hebrew verb covers both looking hard for the hidden and hiding oneself from being found.