If the friends have nothing to say, that is no reason for Elihu's silence. He is full of words, and must give them vent. The fear of God will prevent his showing partiality.
Related Commentaries of Job 32:15
Job 32:15-22
15 They were amazed, they answered no more: they left off speaking.
16 When I had waited, (for they spake not, but stood still, and answered no more;)
17 I said, I will answer also my part, I also will shew mine opinion.
18 For I am full of matter,f the spirit within me constraineth me.
19 Behold, my belly is as wine which hath no vent; it is ready to burst like new bottles.
20 I will speak, that I may be refreshed: I will open my lips and answer.
21 Let me not, I pray you, accept any man's person, neither let me give flattering titles unto man.
22 For I know not to give flattering titles; in so doing my maker would soon take me away.