Certainly the notion of mustard seed growing into a great tree is my favourite absurdity. At least it became so when a Christian asked me what a mustard tree looks like. I thought what??? You read what where? Oh, well I think Jesus was prone to a little exaggeration for reasons of theatre. A humorous chap no doubt.
Hey, I'm gonna let you in on a little secret. An all-powerful being can create a great tree from a mustard seed because it's all-powerful. Just thought I'd let you in on that little secret..