Job 29:9
Hebrew Bible
7 When I went out to the city gate and secured my seat in the public square, 8 the young men would see me and step aside, and the old men would get up and remain standing; 9 the chief men refrained from talking and covered their mouths with their hands; 10 the voices of the nobles fell silent, and their tongues stuck to the roof of their mouths.
Sirach 5:12
Ben Sira, Ecclesiasticus
Deuterocanon
11 Be quick to hear, but deliberate in answering. 12 If you know what to say, answer your neighbor; but if not, put your hand over your mouth. 13 Honor and dishonor come from speaking, and the tongue of mortals may be their downfall.
Notes and References
"... Job expects their silent attention when he himself speaks (Job 13:13, 17). Later on, he reminds his friends of previous times, when he still received respect from the community. In the past, when he spoke people were silently listening to him (Job 29:9-10, 21-22). It is quite clear that Job considered himself a wise king whose argument could not be countered. What should be avoided above all is self-praise ... The late book of the Wisdom of Ben Sira gives all kinds of reasons for silence between people, but stresses especially the wisdom of biding your time ..."
Korpel, Marjo C. A. The Silent God (p. 94) Brill, 2011