These are two-part allegorical sayings. The first part, which is always stated, is the literal meaning of the expression. The second part is the unstated, implied meaning of the expression.
A Buddhist monk holding an umbrella – there is neither law nor heaven. This idiom means to be completely lawless. To understand why, you need to know that 法fa which means law is pronounced the same way as 发fa which means hair, and that 天tian means both sky and heaven.