Verse 19 Till I swallow down my spittle? - This is a proverbial expression, and exists among the Arabs to the present day; the very language being nearly the same. It signifies the same as, Let me draw my breath; give me a moment's space; let me have even the twinkling of an eye. I am urged by my sufferings to continue my complaint; but my strength is exhausted, my mouth dry with speaking. Suspend my sufferings even for so short a space as is necessary to swallow my spittle, that my parched tongue may be moistened, so that I may renew my complaint.

How long - How long will it be ere thou withdraw thy afflicting hand? Swallow - That I may have a breathing time: a proverbial expression.

Job 7:19

How long wilt thou not depart from me? rather, Wilt thou not look away from me? (see the Revised Version). Job does not go so far as to ask that God should "depart from" him. He knows, doubtless, that that would be the extreme of calamity. But he would have God sometimes turn away his eyes from him, and not always regard him so intently. There is something of the same tone of complaint in the psalmist’s utterance; "Thou art about my path, and about my bed, and spiest out all my ways" (Psa 139:3, Prayer-book Version). Nor let me alone till I swallow down my spittle? Even, i.e; for the shortest space of time passible. A proverbial expression.