Vayikra Rabah (27:2): Who praised Me, before I gave to him a Neshamah? Who circumcised his son, before I gave to him a son? Who made a railing around his roof, before I gave to him a roof? Who affixed a Mezuzah, before I gave to him a house? ...

'Rashi': Who came before Me to serve Me, and I will pay his reward to him.

Ibn Ezra: This is like two who feud, and each tells the other 'I you will defeat me, I will give to you this amount.'

Ramban (4): Who fought the Livyasan, before I said this?

Malbim: Hashem showed that one cannot destroy His great awesome creations, e.g. Behemos and Livyasan, for they are a sign of His power. He had empowered Iyov to do so, for so Iyov wanted. Did Hashem owe Iyov, and due to this He must hand over to him to do as he wants to all Hashem's giant creations?! Or, did you help to create them?! It is enough that I created you amidst pure Chesed - you did not do anything for Me before this!

'Rashi': I am able to pay his wage.

Ibn Ezra: Therefore, I could pay if he would defeat me (refer to 41:3:1:3).

Ramban (4): If one will defeat the Livyasan, I can give to him great wealth, for all is Mine!

Malbim: How do you request that I hand over to you everything under Shamayim?!