Reference for Sanhedrin 203:4
(מלכים א יא, כט) ויהי בעת ההיא וירבעם יצא מירושלם וימצא אותו אחיה השילוני הנביא בדרך והוא מתכסה בשלמה חדשה תנא משום רבי יוסי עת היא מזומנת לפורענות
R. Johanan explained this: The Holy One, blessed be He, said, 'They have gone deeper [i.e., are more stringent] than I. I said, "Whoever does not go up [to Jerusalem] for the Festival violates a positive injunction" whereas they proclaimed, "Whoever does go up for the Festival will be pierced with the sword."'<span class="x" onmousemove="('comment',' Thus they forbade more severely than I had commanded it. ');"><sup>6</sup></span> And it came to pass at that time when Jeroboam went out of Jerusalem, that the prophet Ahijah the Shilonite found him in the way, and he had clad himself with a new garment:<span class="x" onmousemove="('comment',' I Kings XI, 29. ');"><sup>7</sup></span>