"看到他那么痛苦" 可以用英文表示为 "seeing him in such agony" 或 "witnessing his agony."
这句话的来源可能指的是看到别人在痛苦中的样子。例如：
"I couldn't bear seeing him in such agony. It was heart-wrenching." (我看不下去他那么痛苦，太伤心了。)
"As I watched him writhe in pain, I knew I had to do something to help." (当我看到他痛苦地扭动着时，我知道必须要做点什么来帮助他。)
痛苦是指人在身体或心理上的疼痛或折磨。它可以是物理的疼痛，也可以是心理上的痛苦，如悲伤、恐惧或绝望。