Although Dogen was well versed in the sutras and refers to them often (especially the Lotus Sutra), it seems he regarded the Zen records as the preeminent expressions of enlightenment. At least this seems to be indicated by the evidence of his records; in his constant reverence for the "words of the ancestors" throughout his work, and moreso by the fact that his citations of the Zen records far outnumber his citations of all the sutras put together. His regard for the Zen records ran so high that in Shobogenzo, Temborin, he even asserted that "the words of an ancestor" could cause the words of a fraudulent or ‘spurious’ sutra to be authentic:
"As to my intention in saying so, there are those who say that the ten-fascicle Shurangama Scripture is a spurious scripture, whereas others say that it is a genuine Scripture: both views have persisted from long in the past down to our very day. There are older translations and there are newer translations, but the one considered spurious is the doubtful translation made during the Chinese Shenlung era (705-706). Be that as it may, the Venerable Abbot Goso Hōen, the Venerable Abbot Busshō Hōtai, and my late Master, the Old Buddha of Tendō, have just now recommended this verse. So, this verse has already been set in motion by the Dharma Wheel of the Buddhas and Ancestors; it is the turning of Their Dharma Wheel. As a result, this verse has already set Them in motion; it has already given voice to Them. Because it is set in motion by Them and sets Them in motion, even were the Scripture a spurious one, if They continue to offer its turning, then it is a genuine Scripture of the Buddhas and Ancestors, as well as the Dharma Wheel intimately associated with Them."
Shobogenzo, Tembōrin, Hubert Nearman
Makes me wonder if I should give the words of those old (not so dead) Zen worthies a little more attention...