Old Taoist wasn't a petty person. Having traveled across lands and experienced countless adventures, he had become a carefree and relaxed person. Even if he ended up receiving no advantage in the end, it was still fate that let him meet this white ape.
Since this was destiny, what was wrong with giving the other some benefits?
Old Taoist took out an edict amulet. This amulet was very old and fragile. He had to be extra careful when taking it out or the amulet might tear.
There was another reason Old Taoist was willing to offer the amulet. This item couldn't be kept for too long. Prior to this, several amulets had gone to waste due to loss of effectiveness or the amulets being damaged.
The remaining two were also giving out soon so why not use it when an opportunity arose? It was definitely better than throwing them out.