Jhāna, seeing the welfare of self and other I am looking for a sutta in which something is said--roughly: that unless one has suppressed the hindrances, one cannot see the welfare of self or other. Or that without jhāna one cannot see one's own welfare or anothers.
Sangaravo Sutta: Sangarava -- The Hindrances (SN 46.55) says that. 

It says that ...


  he cannot know or see, as it really is, what is to his own profit, nor can he know and see what is to the profit of others, or of both himself and others


... when overwhelmed and possessed by hindrances including ...


sense-desires
ill-will
sloth-and-torpor
worry-and-flurry
doubt-and-wavering


... but conversely ...


  when a man dwells with his heart not possessed, not overwhelmed by sense-desires... ill-will... sloth-and-torpor... worry-and-flurry... doubt-and-wavering... [like the five bowls of water not as previously described, but 'clear, limpid, pellucid, set in the open']... then he knows and sees, as it really is, what is to his own profit, to the profit of others, to the profit of both himself and others. Then even sacred words he has not long studied are clear to him, not to mention those he has studied.


This sutta says that about "hindrances" and "profit of self and other", but I don't think it mentions jhāna.