Jump lesson, schooling water

We started in the show jump arena with a cross rail, vertical, taller vertical, and a little oxer.  John had me work on getting him forward, balancing, and then having him continue forward to the jump.  Even if our distance was a little off, if we were in the balanced, forward canter, we could take off from almost anywhere and it felt balanced, even if it wasn't the perfect spot.
The trick here was that when I half halt, to balance him, I MUST put leg back on afterwards, and not let him putter down.
Then we went out and rode the water.  Well, first John had us jump a roll top (a couple times), then the brushy vertical to the water, which Duke just stopped at.  I looked down, tilted forward, it was a classic bad ride.
John had me hit him.  Duke's mind was blown.  I thought he was going to have a melt down, he stood with his neck rigid and his heart thumping, but when I asked him to go forward, he pulled his shit together.  He was heavy and downhill, but he went into the water.  Over and over again.  John put up guiding poles, on the fence and on the edge of the water, to keep him in the water, instead of trying to jump out sideways to avoid landing in it.
John said I need more leg - to close my leg when I feel him hesitate and to look up.  So it's the same as the show jump ride, I need to send him forward, balance him, send him forward again, then ride him confidently (assertively) to the fence, leg on, looking up not down, ready to hit him, and RIDE HIM (teeth gritted when I type that) into the water.
He said we'll ride dressage Monday night and then jump him into the water again (deeper) afterwards.