To issue forth is to stream or pour outward from an opening. Smoke issued forth from the door.
It is deliberately old-fashioned and belongs to formal or literary writing. Anything that can issue forth does so in quantity rather than a little at a time.
1phraseissue forthTo stream or pour outward from an opening, said in a formal, old-fashioned way.
“Steam would issue forth from the grating on cold mornings.”
issue forth is a phrase.
Practised in A Song of Ice and Fire