One is so near to another, that no air can come between them.
All Commentaries on Job 41:16 Go To Job 41
Gregory The Dialogist
AD 604
54. These scales of sinners are both hardened and joined together, so as not to be penetrated by any breath of life from the mouth of preachers. For those whom a like guilt associates, the same does a perverse defence also crowd together in obstinate agreement, in order that they may protect each other with mutual defence for their sins. For every one fears for himself, when he beholds another admonished or corrected, and therefore arises with the like feeling against the words of reprovers, because, in protecting another, he protects himself. It is therefore well said; One is joined to another, and not even a breath comes between them; because while they mutually shield each other in their iniquities by their proud defence, they suffer not the breath of holy exhortation in any way to reach them.