Came - literally, was (and in Jeremiah 1:4); the phrase implies that Jeremiah possessed God’s word from that time onward, not fitfully as coming and going, but constantly.
The thirteenth year of his reign - According to the ordinary reckoning, this would be 629 b.c., but if the Ptolemaic canon be right in putting the capture of Jerusalem at 586 b.c., it would be two years later, namely 627 b.c. However, according to the Assyrian chronology, it would be 608 b.c. It was the year after that in which Josiah began his reforms.