“’The LORD Adonai (the true God) said, ‘This people has tempted ME now ten times.’  Now St. Paul comes along and tells who that God was when he says, ‘They tempted Christ.’  Find any loophole you want here, but Paul says that it was Christ, and Moses says that it was one eternal, true God – and, on top of that, at that time Christ was not yet born.  Indeed, neither David nor Mary had yet been born, and nevertheless he simply says, ‘They tempted Christ; let us not also tempt Him.’  From this it certainly follows that Christ is the man about whom Moses writes that He is God.”

Excerpted from Luther’s 1537 Trinity Sunday sermon (on Romans 11:33-36), in Luther’s Works, vol. 78, “Church Postil”.  Edited by Benjamin T.G. Mayes and James L. Langebartels. 2015, St. Louis: Concordia Publishing House. Pg. 20.