《史记·三十世家·鲁周公世家》
成王七年二月乙未日，成王在镐京朝拜武王庙，然后步行至丰京朝拜文王庙，命太保召公先行到洛邑勘察地形。
成王七年二月乙未，王朝步自周，至丰，使太保召公先之雒相土。
On the day of Yiwei in February in Cheng the King's 7th year, Cheng the King went to the Temple of the Martial King at Haojing to pay homage, and then he walked to the Temple of the Literary King at Fengjing to pay homage. He asked the Grand Tutor Zhao Gong to go to Luoyi to investigate the terrain first.