He looked back at the whisperers as if he wanted to say something to them,but thought better of it

问题的关键是think better of,这是一个固定短语,意思是：改变主意,重新考虑
类似的例句：
1. He wanted to speak but thought better of it and held in.
他很想说出来,但仔细想想还是忍住没说.
2. John told his mother he wanted to leave school, but later he thought better of it.
约翰告诉他母亲说他想退学,但后来改变了主意.
3. I was going to go, but I thought better of it.
我原来打算去的,后来又决定不去了.