The word "Du" appeared as early as in Oracle Bone Inscriptions Harmony and occasionally appeared in pre-Qin classics. Shuowen has the word "crossing". So it's not too late. However, in ancient books, "jiao" is often associated with "degree", and it is very common to use "degree" instead of "jiao". The word "Du" appearing in pre-Qin articles is often written as "Du" in another version. It is estimated that "crossing" is not very late, but it is really used less in the early days.
But there are many use cases of "crossing" in later poems. It's just that the meaning of "degree" is wider, so you may see more.
I'm not an expert in this field, so I dare not jump to conclusions. I can only look for some information.
Attach a little information for your reference:
1、
Zhu Duan's Shuowen Volume XI Shuisi
ferry across the river
Gia (The economic seal above doesn't mean this. This is a supplement. Gao Feng said: Economy, crossing also. Dialect says: excessive refers to economic assistance. Wherever you go, you are on vacation. Borrow more. The celestial body is 365 degrees, which means it has passed 365 degrees. ) The sound comes from the water. I cut it. Five. )
2、
Nine words outside the word "Four Seasons" in Kangxi Dictionary
ferry across the river
Tang Yun's Collection of Rhymes only cuts rhymes, and the tone is the same. Said Moon Hee also. Guangya went and returned. ▲ and interoperability. Jia Yi in the former Han Dynasty told the story of the river's death. Rhyme or couplets? .
3、
Notes on Thirteen Classics (18 15 Ruan Yuan Edition), Notes on Er Ya Zhu Shu, Notes on Er Ya Zhu Shu, Volume 5 Notes.
The sixth release device and the crossing of Xiangjiang River [the original and the people-oriented inspection book are the same as the original and the mistake]