If I say, I will forget my complaint - If I resolve that I will leave off complaining, and will be more cheerful, I find it all in vain. My fears and sorrows return, and all my efforts to be cheerful are ineffectual
I will leave off my heaviness - The word rendered "my heaviness" here (פני pânam) denotes literally "my face;" and the reference is to the sad and sorrowful countenance which he had. "If I should lay that aside, and endeavor to be cheerful."
And comfort myself - The word rendered comfort here (בלג bâlag) in Arabic means to be bright, to shine forth; and it would here be better rendered by "brighten up." We have the same expression still when we say to one who is sad and melancholy, "brighten up; be cheerful." The meaning is, that Job endeavored to appear pleasant and cheerful, but it was in vain. His sorrows pressed heavily on him, and weighed down his spirits in spite of himself, and made him sad.

I will forget my complaint - I will forsake or forego my complaining. I will leave off my heaviness. Vulgate, I will change my countenance - force myself to smile, and endeavor to assume the appearance of comfort.

If (u) I say, I will forget my complaint, I will leave off my heaviness, and comfort [myself]:
(u) I think not to fall into these afflictions, but my sorrows bring me to these manifold infirmities, and my conscience condemns me.

If I say, I will forget my complaint,.... The cause of it, the loss of his children, servants, substance, and health, and endeavour to think no more of these things, and cease complaining about them, and attempt to bury them in oblivion, and change his note:
I will leave off my heaviness; his melancholy thoughts, words, airs, and looks; or "forsake my face" (h), put on another countenance, a more pleasent and cheerful one; the Jewish commentators generally interpret it, "my anger", either at the dispensations of Providence, or at his friends:
and comfort myself; that things were not worse with him than they were; or strengthen (i) himself, as the word is rendered in Amos 5:9; against his fears, and troubles, and dejection of mind, determining to take heart, and be of good courage, and not sink, and succumb, and faint under his burdens: none but God, Father, Son, and Spirit, can give comfort to distressed ones, whether on temporal or spiritual accounts; but good men may make use of means for comfort, such as hearing the word, reading the Scriptures, prayer, meditation, and conversation with good men.
(h) "relinquam facies meas", Montanus, Bolducius, Schmidt. (i) "confirmabo vel roborabo cor meum", Mercerus; so R. R.