john 5:18 Therefore the Jews sought the more to kill him, because he not only had broken the sabbath, but said also that God was his Father, making himself equal with God. - Free Bible Online

      18. God was his Father--literally, "His own [or peculiar] Father," (as in Ro 8:32). The addition is their own, but a very proper one.
      making himself equal with God--rightly gathering this to be His meaning, not from the mere words "My Father," but from His claim of right to act as His Father did in the like high sphere, and by the same law of ceaseless activity in that sphere. And as, instead of instantly disclaiming any such meaning--as He must have done if it was false--He positively sets His seal to it in the following verses, merely explaining how consistent such claim was with the prerogatives of His Father, it is beyond all doubt that we have here an assumption of peculiar personal Sonship, or participation in the Father's essential nature.

JFB.