Jamieson, Fausset and Brown on John 1:49

49. Son of God ... King of Israel--the one denoting His person, the other His office. How much loftier this than anything Philip had said to him! But just as the earth's vital powers, the longer they are frost-bound, take the greater spring when at length set free, so souls, like Nathanael and Thomas (see on Joh 20:28), the outgoings of whose faith are hindered for a time, take the start of their more easy-going brethren when loosed and let go.