The answer is: Seven days

Job 2:13 - Seven days was the usual time of mourning. Perhaps they joined him in this period, not that they stayed in one posture for the entire seven days.

In the Book of Job, the silence of Job's friends for seven days is more than just an expression of empathy; it's a powerful act rooted in ancient customs surrounding grief. It wasn't just a random number — in many ancient cultures, including the Hebrew tradition, seven days symbolized completeness or wholeness. This is reflected throughout the Bible, — think of the creation story in Genesis, where God rests on the seventh day after completing the creation.

But here we find that these seven days of sitting silently with Job marked an important transition from friendship to the discussions that followed—ones that would shift job's suffering into debates about divine justice. An interesting aspect about Job's experience is how it flips our perception of suffering and righteousness. His appropriation of grief helps deepen an understanding of human pain as universal and not tied to one’s moral standing.

By resting in silence, they showed that sometimes mere presence can carry the weight of compassion. It’s a reminder that in moments of deep loss, where words often fail and may even hurt more, holding space can be profound. The rich tapestry of encounters in Job also encourages readers to seek meaning beyond conventional views of cause and effect, thereby echoing the deeper notion that life’s complexities often elude our attempts at easy answers and simplified narratives. So the next time you approach a friend in hardship, consider the strength of your silent support—it’s age-old wisdom with perennial relevance!