Recently, a friend of the Cepher wrote as follows:

I have been very curious about the "swearing seven oaths" phrase throughout Bere'shiyth.  One example is chapter 47 verse 31:

And he said, Swear seven oaths unto me. And he swore seven oaths unto him. And Yashar'el bowed himself upon the bed's head.
BERE'SHIYTH (GENESIS) 47:31 את CEPHER

This is a great question which deserves an answer in writing.

Here is the word found in that passage:

Shaba (שָׁבַע) (Strong's H7650) which is a primitive root; meaning properly to be complete, but used only as a denominative from H7651; to seven oneself, i.e. swear (as if by repeating a declaration seven times): i.e., to adjure, charge (by an oath, with an oath), feed to the full (by mistake for H7646), take an oath, × straitly, (cause to, make to) swear.

This has to do with its spelling, which is consistent with Sheba (שֶׁבַע) (Strong's H7651) or (masculine) (שִׁבְעָה shibʻâh); which is also a primitive cardinal number; seven (as the sacred full one); also (adverbially) seven times; by implication, a week; by extension, an indefinite number: i.e., (+ by) seven(-fold),-s, (-teen, -teenth), -th, times).

The word construed as to swear, or to give an oath is inextricably linked with the word seven, and literally means to seven oneself or to swear by repeating a declaration seven times.

There you have it.