2 Chronicles 15:12

And they entered into a covenant
Asa and all his people; that is, as Piscator remarks, they went between the pieces of the calf cut asunder, for the confirmation of the covenant, see ( Jeremiah 34:18 ) ,

to seek the Lord God of their fathers, with all their heart, and with
all their soul;
to serve and worship him most truly, sincerely, and cordially.